Ex Post Facto (episode)
Tom Paris is convicted of murder. He denies having committed the crime, even though the images extracted from the victim's own memory seem to prove his guilt.

Summary

Teaser 

On an alien world, a weary Tom Paris lies down on a bed, his combadge missing from his uniform, while another man asks him what he sees in his mind. Paris replies that he sees "shoes, muddy shoes. The dog." The man in the room tells him that this is exactly what he should be seeing. In Paris' mind, he sees himself kissing an alien woman passionately. Another person, whose point of view Paris is seeing, upon making his presence known, states that he now understands. Paris tells the woman he is with that he had better be on his way. She holds him close and tells Paris that the man has no right. "No right?! You come into my home, steal my wife, and I have no right?!" In reality, Paris insists that this is not the way the incident happened, but the man in the room with him informs Paris that the trial is over and there is no point to further deny anything. Back in the "memory", the man tells Paris he knows of his past spent in prison and that once he informs Paris' commanding officer of his indiscretion, he will never wear his uniform again. Paris insists he cannot let him do that, rushes towards the man and stabs him fatally with a knife.

All these "memory" images are seen in black and white, with alien symbols superimposed on them.

In reality, Paris lies on the bed, seemingly feeling the stabbing. The man with Paris announces that for "the rest of his natural life, once every fourteen hours, Thomas Eugene Paris will relive the last moments of his victim's life. May the fates have mercy on you, sir." Paris is led away by a guard.

Act One 
Aboard the , The Doctor and Kes are in the chief medical officer's office reviewing medical texts. Kes is in training to become The Doctor's medical assistant aboard. During their review, Kes asks the holographic physician if he has given further thought to giving himself a name. The Doctor says he has trouble with making a choice, as holograms do not usually make them. Kes disagrees, mentioning that The Doctor chooses which treatment to give his patients. The Doctor tells her that he is programmed to do that, and that there is no independent decision making involved, but Kes cannot see the difference. She then tells him he should simply pick a name, but tells him to take his time, as he will be known by that name for the rest of his existence. Shortly thereafter, Captain Janeway hails sickbay and tells The Doctor to expect an injured crewman – either  Paris or Ensign Harry Kim.

Kim is beamed directly to sickbay and informs Janeway of some horrifying news: Tom Paris has been convicted of murder and as punishment he has to relive his victim's last moments over and over again. Kim begins a recounting of their activities prior to Paris' conviction of murder: they visited the homeworld of the Banea and met an engineering physicist Tolen Ren. The Voyager crewmen approached Doctor Ren for assistance because the ship had a damaged collimator that required expert assistance. After an initial meeting, Kim and Paris are invited to the professor's home for dinner that evening. While there, the officers meet the professor's young wife Lidell, who is irritated with her husband's lack of manners at not calling first when bringing home guests.

After a brief and tense meal, Kim, the professor and Paris retire to another room to begin work. Paris allegedly got bored and spent some time with Tolen's young wife Lidell. That night, Professor Ren was murdered. Kim tells Janeway that the Banea questioned him for two days straight, asking him a lot of questions about the Banea's enemy, the Numiri. Kim surmises that the Banea must have thought he and Paris were Numiri agents spying on them. Kim also informs Janeway that Professor Ren was the inventor of Banean warship technology. The Doctor wants Kim to get some rest, so Janeway has her first officer, Commander Chakotay, set Voyager on a course for the Banean homeworld to find some answers.

Act Two 

Once they arrive, Janeway and chief of security Tuvok beam down to talk with Paris about the crime. They meet with Minister of Science Kray. Kray explains that Tolen Ren was stabbed to death in his living room in front of Lidell. Paris was arrested and convicted of the murder. Kray tells the Starfleet officers of Paris' sentence: to relive the crime through the victim's eyes once every fourteen hours for the rest of his life. This was done by examining the victim's memories and implanting them into Paris' brain. Janeway and Tuvok later meet with Paris, and he tells them the "rehab colony back in New Zealand doesn't seem so bad right now." Tuvok asks Paris if he killed Professor Ren and he forcefully denies having killed him even though he did spend some time with his wife Lidell. Paris recalls finding Lidell looking up at the sky and smoking, stating that "her eyes were a million kilometers away, staring at stars I'd just flown by a day before," and engaging her in polite conversation in the atrium. He tries to comfort her over her marital problems wherein she admits she married the much older Professor Ren because he was kind to her.

Lidell apparently ended her marriage to the professor and proceeded to pursue Paris. Paris and Lidell spend more time together. Soon after, Tolen heard about Lidell's relationship with Paris and confronted her. Immediately afterward, Paris relives the murder once again and loses consciousness. Janeway asks the Banean minister to take him to their ship for a medical evaluation from Voyagers chief medical officer. Kray reluctantly agrees but warns Janeway not to leave orbit. Janeway retorts that they do not plan on leaving until they prove Paris' innocence and Tuvok calls Voyager for three to beam aboard.

Act Three 
Soon after, Tuvok visits the murder scene and speaks with Mrs. Ren. She says that she witnessed the murder and that it has in fact been committed by Paris. Tuvok notes that he finds Mrs. Ren to be dispassionate and she engages him in playful verbal sparring. She asks Tuvok if he has ever had to end a marriage. He tells her he has not;  and himself have been married for sixty-seven years. She tells Tuvok she was about to leave her husband of ten years for Paris, which Tuvok finds hard to believe as Paris was to depart the planet for good in only a few days. She tells Tuvok that meeting Paris gave her "the push I needed." She recalls seeing Paris again the day of the murder, knowing that he wanted to see her. She recalls kissing him during a cloud burst of rain. While outside kissing her, Paris did not think it was appropriate, as she was still married to her husband. She told Paris that her husband had not treated her like a woman since the day they had viewed an eclipse together four years previously.

Lidell tells Tuvok she made him Marob root tea to warm themselves up, they watched the storm from the atrium… and the rest Tuvok knows. Tuvok receives a signal through his combadge; Chakotay informs him that Paris has regained consciousness and thought he would like to know. Tuvok prepares to be beamed up to Voyager but before he leaves, Lidell asks Tuvok if he could tell Paris that she forgives him for her husband's murder.

Back on Voyager, Tuvok decides to conduct an autonomic response analysis scan on Paris to determine if he is telling the truth. The ARA scan confirms that Paris is being truthful when he says he didn't murder Tolen, but can't offer another explanation. The Doctor asserts that there were no drugs in Paris' system. Suddenly, the Baneans' enemy, the Numiri, attack Voyager. Chakotay hails Tuvok and tells him to report to the bridge.

Act Four 
Chakotay, who is handling the helm controls in Paris' absence, manages to defeat the Numiri with an old Maquis trick. He reminds a nearby B'Elanna Torres of their defeat of Starfleet runabouts at Teluridian IV. She understands immediately and from her station on the bridge, orders engineering to vent Voyagers LN2 exhaust conduits along the dorsal emitters to make the ship look like it is in serious trouble. The plan works and the Numiri patrols are disabled by Voyagers phasers. Janeway tells Chakotay that that is one trick he will no longer able to perform when they return home. He remarks that he has more. Janeway has the ship stand down from red alert. Tuvok informs Janeway that due to the urgency of Paris' situation, he proposes he observe the crime himself by performing a mind meld on Voyagers helmsman.

In sickbay, Tuvok is preparing to perform the mind meld with Paris, over The Doctor's strenuous objections. The Doctor reminds Tuvok that Paris' brain is suffering from degradation from the implanted memories and he has no idea what melding with it will do to a Vulcan brain. Tuvok believes the risks are acceptable. During the mind meld, Tuvok makes note of several points of interest in the "memory", such as the height of both Paris and Lidell, the alien symbols and numbers, and the location of the knife on Professor Ren's body. Breaking the meld, The Doctor examines Tuvok and can find no brain damage. Tuvok tells Janeway he now understands why Paris is convicted of the murder and why the Numiri chose to attack Voyager. Tuvok subsequently confers with Ensign Kim to confirm his suspicions. To further confirm his suspicions, Tuvok has the captain use Tom Paris as bait.

Act Five 
Specifically, Janeway sends Kim and Paris back to the planet in a shuttle under the pretext that further use of the transporter could cause medical complications to Paris. This draws out the Numiri and they seize the shuttle and try to take Paris hostage. The two crewman are beamed away. Janeway threatens to detonate a cache of explosives hidden on the shuttle unless it is released.

At a meeting at the scene of the crime the following day, Tuvok reveals that Lieutenant Paris was not the man the professor saw before he was murdered. Tuvok elaborates that he believes that someone altered the memory engrams of the professor's brain. He points out the stream of numbers and text which appear in the memory which he believes is from the professor's weapons research.

He also reveals that Lidell's statement was false: the man the professor observed with his wife was virtually equal in height with her, however, Tom Paris is clearly several centimeters taller. Moreover, the killer – unlike Paris – knew Banean anatomy, for he knew exactly where to stab the professor to ensure a fatality. Lastly, the equations Paris sees in his memory are not at all typical to the procedure but rather equations taken from Dr. Ren's weapons research: someone intended them to be delivered to the Numiri – thus sending secret data to the enemy by using Paris' presence to their advantage. In other words, he would never be suspected of aiding an enemy because he is not a native of the planet and has no vested interest one way or another. That is why they were attempting to attack Voyager: they wanted to board the ship and take Paris by force.

Tuvok names the doctor who performed the memory transplant on Paris as the real killer of Dr. Ren, and Lidell as his accomplice. The Banean Doctor said that he has never been in this house before today. Tuvok proves his final point by referring to the second witness to the murder: the victim's pet dog Neeka that clearly recognized the doctor and was familiar with him when he entered the room, proving the Banean Doctor is a liar. Lidell tries to tell Paris before she is led away that she never meant to hurt him but he takes her hand away from him and tells her she did.

Later in Voyagers mess hall, Paris thanks Tuvok for having saved his life but Tuvok states that he merely conducted a criminal investigation searching for the truth and that Paris doesn't owe him anything. Paris thanks him anyway, stating that whether Tuvok likes it or not, he made a friend today.

Memorable quotes
"Smoking is a bad habit. My species gave it up centuries ago when we finally got it into our heads it was killing us."
"Maybe I kill myself slowly because I don't have the courage to do it quickly."
 - Tom Paris and Lidell Ren

"What are you looking at?"
"Not the same thing you're looking at, that's for sure."
 - Tom Paris and Harry Kim, after Kim notices Paris' interest in Lidell Ren

"What are you looking at?"
 - Tom Paris, to Neeka, the Ren's canine

"Besides, out here in the Delta Quadrant every old trick is new again."
 - Chakotay

"What do you see?"
"Shoes… muddy shoes. The dog."
"Good. That's exactly what you should see."
 - Banean doctor and Tom Paris, as Paris relives Tolen Ren's last memory

"You don't have to go, Tom. He has no right."
"No right? This is my home, you come into my home, steal my wife and I have no right?!"
 - Lidell and Tolen Ren in Paris' "memory"

"I propose a mind meld with Lieutenant Paris."
"A… a what? What did he say? A mind what?"
 - Tuvok and Neelix

"There are some who'd say you risked my future on the eyewitness identification of a dog."
 - Tom Paris, to Tuvok

"Her eyes were a million kilometers away, staring at stars I'd flown by the day before."
 - Tom Paris, on Lidell Ren

"I was bored. You know how it is when two science guys get together."
 - Tom Paris

"I appreciate you sticking up for me. I owe you one."
"I conducted a criminal investigation. If you had been guilty, I assure you, I would have pursued the truth just as vigilantly. You have no debt to me, Mr. Paris."
 - Tom Paris and Tuvok

"How come I always see you down here eating alone, Lieutenant?"
"I prefer to read rather than engage in… what do Humans call it… short talk?"
"Close enough."
 - Tom Paris and Tuvok

"Blowing out the dorsal phase emitters. Torres to engineering."
"Go ahead."
"Vent a couple of LN2 exhaust conduits along the dorsal emitters. Make it look like we're in serious trouble."
 - Torres and unidentified comm voice; the line that gave Roxann Dawson difficulty (see below).

"That's one trick you won't be able to use again when we get back."
"I have more."
 - Janeway and Chakotay

"Very, very curious. In Numiri terms, that greeting was downright friendly."
 - Neelix

"That rehab colony back in New Zealand doesn't seem so bad right now."
 - Tom Paris

Background information

Title, story, and script
 
 The ultimate resolution of the mystery is lifted directly from Sherlock Holmes.  In the case of "The Adventure of Silver Blaze," the criminal was also detected by a dog - one who did not bark at the criminal because they were previously acquainted.  This gave rise to the phrase, "the curious incident of the dog in the nighttime," which led to a novel and later Broadway play of the same name.
 The scene where Tuvok reveals the true identity of the murderer, is also reminiscent of Agatha Christie novels involving detective Hercule Poirot, who often gathers the suspects at the location of the crime to reveal the truth. In the story, Mystery at Hunter's Lodge, also involves the final reveal of the murderer by means of a dog, though this time by scent rather than by identity.
 The original idea that formed the basis of this episode involved the concept of a species who, as a means of punishment, forced the perpetrator to experience their victim's death and the last few moments of the victim's life. (Sci-Fi Universe, October 1995, p. 63; Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140)
 After the writers bought the premise, Executive Producer Michael Piller took the episode in a direction whereby it also served as an homage to film noir. Fellow Executive Producer Jeri Taylor said of the original story idea, "It became […] a sort of a murder mystery device." (Sci-Fi Universe, October 1995, p. 63) Supervising Producer David Livingston remembered, "Piller wanted to do film noir […] And then he wrote all this noir dialogue, literally […] It was Michael's homage to film noir. Michael was really into  at the time and he said, 'Everything should be like Pulp Fiction.' I think this was his Pulp Fiction." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140)
 Scripting the episode was enjoyable for Michael Piller. He recalled, "I was working on this episode and I think it had a lot of original science fiction ideas [such as the installment's premise as well as the concept of information being smuggled via someone's brain] […] Taking those elements and [trying to weave] them into a story that was affecting and intriguing was difficult, and I had a great deal of fun getting into my trench coat and going to my word processor and doing it." (Sci-Fi Universe, October 1995, p. 63; Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140)
 This episode's final draft script was submitted on .  The teleplay continued to be revised thereafter, however, with one subsequent script revision made on . A scene that was changed with that revision was the one set in a shuttlecraft, featuring Paris and Kim discussing the former's interactions with Lidell Ren. The scripted version of that scene started with the scene description "Paris looks weary… Kim intense…". The final version of the conversation includes Paris saying "Yeah" and later sighing to Kim, actions that were not scripted. (A Vision of the Future - Star Trek: Voyager, p. 173)

Cast and characters
 This episode's script was one of about a half-dozen that were written prior to the casting of Tom Paris. It therefore treats Paris in the same way as the character was originally conceived – as an habitual womanizer, like James T. Kirk and William T. Riker (A Vision of the Future - Star Trek: Voyager, p. 174).
 As a result, Jeri Taylor ultimately thought this episode marred the character of Tom Paris, owing to the fact that the story – despite making clear that Paris' actions were not exactly as depicted by the implanted memory device – seems to suggest that he came to Banea and began hitting on the wife of one of the planet's inhabitants. Taylor remarked, "I was concerned that our Tom Paris was not well served. His behavior was somewhat questionable." (Cinefantastique, Vol. 27, No. 4/5, p. 47) She later said, "It was a very unattractive posturing for him. That's the kind of cliché the character could easily fall into. By that point, I was really fed up with it […] It was very one dimensional, very unattractive." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140)
 For his part, Michael Piller acknowledged, "['Ex Post Facto' was] a subject of mixed opinions, because Jeri felt we had done some character damage to Paris. I thought he came off rather well." () Piller also noted, "I thought it was a wonderful show for Paris." (Cinefantastique, Vol. 27, No. 4/5, p. 47) Further recalling his disagreement with Taylor, Piller said, "Jeri and I had a real argument over what the impact of 'Ex Post Facto' was. She felt we had assassinated his character in that picture […] The idea that he would even consider a relationship with a married woman she found quite distasteful. She felt he looked like a low-life womanizer. I think that he has a character flaw, a weakness, that I can appreciate. I think a lot of men can appreciate that and that he fell victim to that flaw – but rose above it to achieve. Jeri can forgive some flaws and she can't forgive other flaws. Infidelity is one that she can't forgive." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 128)
 The book A Vision of the Future - Star Trek: Voyager (pp. 172 & 174) cites Paris' situation in this episode as an example of a character arc that typically dramatizes a situation that many viewers can relate to (specifically, temptation to have an affair with a married person).
 Paris actor Robert Duncan McNeill was delighted with this installment's script. Shortly before production on the episode commenced, he raved, "[It] has one of the best scripts I've ever seen. It was so good I had to call Michael Piller and thank him for it […] I can't wait to shoot it." ( #213) The episode's unusualness had an influence on the way that McNeill viewed the installment. "It was interesting for me as an actor," he said, "because it was a little bit different in style." He felt this episode was let down, however, by its murder-mystery quality and especially the plot's conclusion. "It was written in a very -ish tone," he observed. "What didn't work about it was the way it ended up being like a  episode, with all the characters sitting around, and here's the big summary of what really happened. The structure of that episode didn't quite resolve itself, but a good part of that episode was really interesting. I thought the idea of crime and punishment, where the criminal has to relive his victim's experience was a great premise and perfect for Star Trek." ()
 The episode was a highlight for Tuvok actor Tim Russ, who appreciated the way it illuminates his character's problem-solving skills. "You got to see how this character can solve a problem, which is typically Vulcan," he said. () Another aspect here that Russ liked was the mind meld sequence. He commented, "I really enjoyed it […] I love the fact that we get to see the mind-meld from the inside out and got a chance to actually go inside [Tuvok's] mind and see the meld from his point of view, which [had] never been done. I thought it was just great." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) The actor also related that he preferred this episode to the later first season installment  but that he enjoyed the way both episodes show Tuvok solving a different kind of problem. ()
 Both Michael Piller and director LeVar Burton liked Tuvok's involvement in this episode. Piller noted, "I thought it was […] a wonderful show for Tuvok." (Cinefantastique, Vol. 27, No. 4/5, p. 47) Burton commented, "Having Tuvok be this great sleuth, this great detective figuring out the murder, was fun." ()
 Another of the episode's elements that Michael Piller enjoyed was the performances of its cast, feeling that the episode had "terrific performances." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140)
 Actress Roxann Dawson did little preparation for her small part of the episode. Dawson recalled, "I was just getting the hang of getting my mouth around the technobabble, and I was just beginning to do it. I was actually feeling a little bit cocky. In that episode, I only had one line – I had nothing to do. We were on the bridge, so I decided that I was OK enough to look at the lines on the morning, and then come in. It would be OK – it was just one line." ()
 Neeka, the Banean dog, was actually a Chihuahua whose hair was teased and blow-dried. (, p. 28)

Makeup
 Makeup supervisor Michael Westmore said of his Numiri design for this episode, "They're a bit on the reptilian side, and it's a full head with a lower lip and very interesting nose to it." ()

Production

 At a meeting pertaining to this installment, David Livingston read aloud the episode's script (or, at least, the start of the script). ("A Day in the Life of Ethan Phillips", VOY Season 2 DVD special features)
 The episode's production was intentionally inspired by its film noir influence. David Livingston recalled, "[Piller] wanted to shoot it in black and white […] Then I suggested a peekaboo haircut for the woman so that she looked like . I figured if you're gonna do it, go all the way." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) This degree of influence was facilitated by the involvement of LeVar Burton – who, with this installment, became the first former  cast member to direct an episode of Voyager. Robert Duncan McNeill noted about the episode, "LeVar Burton shot it in a film noir style." ()
 During filming of the mind meld scene between Paris and Tuvok, Tim Russ suddenly threw back his head and launched into his best James Brown impression, yelling, "I'm feeeeelin' goooood!" (, p. 28) Following this experience, Robert Duncan McNeill remarked, "I have Tim Russ to thank for the most memorable mind-meld of the century when he broke into a James Brown impression and caught me completely off-guard in the middle of a scene in the episode 'Ex Post Facto'." 

 The scene in which Torres acts on Chakotay's plan of making Voyagers systems seem seriously troubled, in order to deceive the Numiri, was filmed on Paramount Stage 8 (the Bridge set) on Tuesday, , while the theme tune for the series and other music for  was meanwhile being recorded on a scoring stage a block away. (A Vision of the Future - Star Trek: Voyager, p. 340 & 341) Having done little preparation for the scene, Roxann Dawson struggled with the dialogue during production. She said, "Of course, they had a lot of interviewers and reporters on the set that day, and I could not for the life of me get it. At one point, [LeVar Burton] put [his] arm around me, and [he was] walking around the bridge going, 'It's OK – all you have to do is …', and I was thinking, 'No, you don't understand; I really can do this. I'm being an utter and complete idiot today, and you're giving me this pep talk.' For the life of me, I could not spit this line out […] 'Vent a couple of LN2 exhaust conduits around the dorsal emitters' […] I felt so bad!" ()
 The next day, filming started at 10:00 am and included shooting of the final scene of this episode – with Tuvok and Paris conversing in the mess hall. LeVar Burton had lined up a shot of the two characters talking, and filming of the scene began. The take was going well but Director of Photography Marvin V. Rush abruptly stopped the shooting. With a touch of irritation in his voice, Burton said, "Cut." Puzzled, Burton asked Rush what was wrong. Rush complained about the sequined curtain used for the starfield outside the mess hall "windows," having noticed a problematic shimmer in the curtain as it had moved; the curtain was meant to move smoothly and uniformly along the overhead track near the stage's ceiling. Also, the curtain was by now a washed-out gray which would result in the starfield, on film, looking like a gray shimmering mass. Chief Lighting Technician Bill Peets was familiar with the problem, as it had happened many times before. Peets conferred with Rush, walked over to the curtain and then pointed out the shimmer. He then moved aside, shouted instructions to lamp operators Ken Suzuki and Bob Eyslee, who immediately adjusted some of the lamps. As the curtain was so heavily sequined, it was difficult to light without it entirely turning gray, but the adjustments solved the problem and Burton proceeded to again set up the shot. Bill Peets walked away from the curtain, murmuring, "God, I hate that thing. $25,000 and it still doesn't work." (A Vision of the Future - Star Trek: Voyager, pp. 342-343)
 The following day – Thursday,  – was the last day of filming before the Christmas hiatus. (A Vision of the Future - Star Trek: Voyager, p. 345)
 Ultimately, LeVar Burton enjoyed having worked on this episode. In summation, he said, "That was a very, very cool episode for a director. It was the first time in Star Trek history we ever shot on black-and-white film stock […] What I loved about that episode was not only the chance to do something that we had never done, but just the nightmare and the murder-mystery aspect […] That was also the first mind-meld we've seen in a long, long time. So, shooting that was fun, too." ()
 LeVar Burton's participation in the episode's production was appreciated by Tim Russ and Michael Piller. Russ declared, "I thought LeVar Burton did a great job of directing the stylized film noir." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) Likewise, Piller admitted, "I felt the direction was great." (Cinefantastique, Vol. 27, No. 4/5, p. 47)

Sets and props 
 The wall decoration seen in Minister Kray's office was previously seen in Proconsul Neral's office in the  fifth season episodes  and , in the barbershop aboard the Enterprise-D in the sixth season episode , in the reception area at Arkaria Base in the episode , and in the observation lounge in the seventh season episode . It will be re-used later and appear in Neelix's quarters in the episode  and in Annorax's ready room aboard the Krenim weapon ship in the fourth season episode .
 The wall sculptures on both sides of the door to Tolen Ren's house later appear as a set dressing in Annorax's house on Kyana Prime in the fourth season episode . In the latter episode they were upgraded with golden elements.

Visual effects
 Evidently, the production crew reused a stock matte painting to depict the surface of Banea. Although the cityscape made no subsequent appearances after this episode, it had previously been used to represent a city on the planet Angel I (from the  first season episode ), Starbase 515 (from ) and Klaestron IV (from ).

 The battle between Voyager and the two Numiri patrol vessels was planned by Jim Rider, David Stipes, Joe Bauer, and Dan Curry, using Styrofoam mock-ups. (Cinefantastique, Vol. 27, No. 4/5, pp. 56 & 57)
 The Numiri ship studio model that was visually duplicated for the battle, in its final composite, was actually a frequently reused model.

Music
 The music for this episode was composed by Dennis McCarthy. He invested a lot of energy in the episode, even more so than he had for . He commented, "I even worked harder on 'Ex Post Facto' than I did on the movie. I mean, that episode was a murder trial with the dog as the surprise witness! I really had to sell that." ()
 Of the seven scores that Dennis McCarthy wrote for Star Trek: Voyagers first season, he ultimately considered this episode to be his favorite as well as the one that involved the most unusual Star Trek music. He noted, "It was a very late 19th Century Impressionist-style score. It was something so different from the normal Star Trek score that, until 'Heroes and Demons,' I was going to submit that one for Emmy consideration." ()
 Michael Piller was pleased with the music for this episode. He noted, "It had a wonderful score." (Cinefantastique, Vol. 27, No. 4/5, p. 47)

Reception
 Both Jeri Taylor and Michael Piller liked this episode's punishment-related premise, Taylor describing it as "sensational" and "a great sci-fi premise." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) She also enthused, "It was one of those great sci-fi notions that you can't do anywhere else and is perfectly legitimate. It says a lot of things about punishment and rehabilitation." (Sci-Fi Universe, October 1995, p. 63) With similar enthusiasm, Piller characterized the initial idea for the episode as "neat." (Cinefantastique, Vol. 27, No. 4/5, p. 47) He believed that both the original premise as well as the concept of someone using another person's brain to smuggle information were "terrific" ideas and implied that he thought his attempt to make the installment "affecting and intriguing" had been successful. (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) He also enthused, "I really loved that episode […] What was interesting was that it really didn't turn out to be so much about crime and punishment as it was about aliens of different sorts, attacks and space battles, all of which were tied together in a very interesting way. I was very happy with that show. I got a good kick out of it." () In addition, Piller said, "I thought it had all the elements of Star Trek and science fiction working for it. It had a really strong mystery, a very strong style; it had space battles; it had investigations with Tuvok at the core of it, so we could see what he does for a living; it had sex and romance." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) Piller also stated, "I just thought it worked on every level. I thought it was sexy, I thought the science fiction was terrific […] It kept you guessing until the very end of the show." (Cinefantastique, Vol. 27, No. 4/5, p. 47)
 On the other hand, Jeri Taylor was considerably less satisfied with the episode's final version than Piller was. She commented, "This to me was absolutely the least successful story that we did. Michael [Piller] feels that it was one of the best that we did. We are at odds over this, as we are occasionally." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) Specifically, Taylor did not approve of Piller's work on the installment; she instead felt that the episode was styled too much like a 1940s American film noir production, especially considering that the series for which the episode was written promised that its settings would be far from Earth. "[It] has suburban housewives, dogs, smoking, and people talking like they came out of a Raymond Chandler novel," Taylor observed. "That seems to me not to be the right thing conceptually, although I think there was a lot of fun to be had in that episode." (Cinefantastique, Vol. 27, No. 4/5, pp. 40 & 47) Michael Piller's referential approach to the episode was controversial with other production staffers as well. David Livingston noted, "It was questioned why they were speaking American 1940s dialogue. It was a little bit on the nose in that regard." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140)
 A certain part of the episode that David Livingston enjoyed was the installment's teaser. He opined, "The opening sequence was effective and interesting." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140)
 This episode achieved a Nielsen rating of 8 million homes, and a 12% share. 
 Cinefantastique gave this installment 1 out of 4 stars. (Cinefantastique, Vol. 27, No. 4/5, p. 40)
 In their unofficial reference book Trek Navigator: The Ultimate Guide to the Entire Trek Saga (pp. 78 & 79), co-writer Mark A. Altman rates this episode 2 and a half out of 4 stars (defined as "average") while fellow co-writer Edward Gross ranks the installment 1 out of 4 stars (defined as "lousy").
 The unauthorized reference book  (p. 30) gives the episode a rating of 7 out of 10.
 In the lead-up to this episode's VHS release,  reviewer Stuart Clark reviewed the episode, stating, "Tuvok does an excellent impression of Hercule Poirot." () In Star Trek Magazines retrospective "Ultimate Guide", the magazine gave this episode 2 out of 5 Starfleet-style arrowhead insignias. ()
 Being very proud of this episode in general, Michael Piller enjoyed watching the installment. He reminisced, "It was one of my prouder moments of sitting home watching television […] I was just really happy sitting down and watching that." (Cinefantastique, Vol. 27, No. 4/5, p. 47)
 Consequently, this episode was a potential Emmy candidate not only for its music but also, so thought Michael Piller, for its overall production. Piller explained, "I called up LeVar and told him that he should submit this one for Emmy consideration." ()
Daniel Keys Moran believes his pitch to  was used without his getting due credit. He commented: "I really disliked 'Ex Post Facto', the episode that borrowed from me. I'd have been predisposed to dislike it anyway, but I hardly needed the predisposition. Hate to think I was borrowed from for the sake of that. Voyager really has quite a fine cast; but its writers don't appear to understand SF -- the very first episode of this show, the space-traveling aliens didn't know how to make water -- 'Burn the hydrogen, guys'. The mystery in "Ex Post" was mediocre, and the dialog was really painful. Everything else aside, my hopes for Voyager are plummeting steadily. Babylon 5, on the other hand, is pretty cool, despite occasional lapses -- mostly the "aliens as humans" stuff that tv SF seems unable to get away from". 
 Also according to Michael Piller, the portrayal of Paris in this episode was not received well by some viewers. Remarking on the episode in general, Piller noted, "A lot of people had questions about it." He added, "They thought we made Paris and his approach to women unattractive." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) Jeri Taylor fully intended for this problem to be dealt with, stating at the time, "We are going to have to do some stories that redeem him. I don't want him to become the randy guy whose only character note is that he's trying to get laid." (Cinefantastique, Vol. 27, No. 4/5, p. 47) Later, Taylor said, "After episode six, I didn't allow any more smarmy womanizing references to go through, because that's all we were saying about his character […] Unfortunately, we didn't replace it with anything else, so Tom Paris didn't do much of anything. That's why we needed to develop him in the second season into something more heroic." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140)
 Having struggled with her one line of technobabble in this episode, Roxann Dawson thought the worst part of the incident was that a story about her struggle was subsequently publicized. She recalled, "Because there [had been] all those reporters there, the first magazine that I opened had a picture of [LeVar Burton] and me captioned, 'LeVar trying to give Roxann a pep talk because she can't do the technobabble on the show.' That taught me never to be cocky again and think I could just get a line on the morning. That was the only line I had in [that] episode, and I was thoroughly and completely embarrassed." Dawson additionally related, "To this day, it's the only line I can still remember like the back of my hand […] I will always remember it because of the pressure of that day." ()

Continuity 
 This episode marks the first performance of a mind meld on Star Trek: Voyager. Tuvok would go on to perform several mind-melds throughout the series.
 In this episode, Tuvok reveals he has been married for sixty-seven years, placing his wedding in 2304.
 Tuvok is still a lieutenant in this episode, and is addressed as one, but he has the rank pips of a lieutenant commander throughout the episode. He is not promoted to that rank until the fourth season episode .
 This episode bears several similarities to the TNG episode , although Michael Piller rejected the notion that this episode was a remake of the earlier one. (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 140) It also bears similarities to DS9's , where O'Brien is falsely convicted of espionage and is forced to experience twenty years' imprisonment in a matter of hours.
 According to the book Delta Quadrant (p. 150), light fittings that can be seen in Lidell Ren's home here were later reused in Henry Starling's office in the Season 3 two-parter  and . While identical-shaped light fittings appear in both productions, they seem to be additionally covered by a metallic-looking framework in the two-parter.
 This is the only Star Trek: Voyager episode in which any character is seen smoking. Tom Paris' negative feelings about the activity echo those of Gene Roddenberry, such as he expressed during production on . On Star Trek: Voyager, Jeri Taylor was likewise opposed to showing smoking. (A Vision of the Future - Star Trek: Voyager, p. 255)

Trivia 
 Among the names The Doctor considers for himself are "Dr. Galen," "Dr. Salk" and "Dr. Spock" (although the scene is scripted in such a way that the viewer might think he is referring to Mr. Spock).

Video and DVD releases 
 UK VHS release (two-episode tapes, CIC Video): Volume 1.4, catalog number VHR 4004, 
 As part of the VOY Season 1 DVD collection

Links and references

Guest Stars 
Robin McKee as Lidell Ren
Francis Guinan as Kray
Aaron Lustig as Banean Doctor
Ray Reinhardt as Tolen Ren

Co-Star 
Henry Brown as Numiri Captain

Uncredited co-stars 
Derek Anthony as operations ensign
Scott Boardman as Banean guard
 as Neeka
Julie Jiang as operations lieutenant junior grade
Jaehne Moebius as sciences officer
Louis Ortiz as Culhane
S. Sanders as command officer
Lydia Shiferaw as command officer
Lou Simon as Banean guard
Jennifer Somers as sciences officer
Simon Stotler as operations ensign
John Tampoya as Kashimuro Nozawa
Ondar Tarlow as sciences officer
Debra Waters as command ensign
Unknown performers as two Numiri officers

Photo double 
Marvin V. Rush – photo double for Ray Reinhardt

Stand-ins 
Carl David Burks – stand-in for Ray Reinhardt
Gyl – stand-in for Robin McKee
Sue Henley – stand-in for Kate Mulgrew
Kerry Hoyt – stand-in for Robert Duncan McNeill
Cy Kennedy – stand-in for Robert Beltran
Nora Leonhardt – stand-in for Roxann Biggs-Dawson
Susan Lewis – 2nd unit stand-in for Kate Mulgrew
Lemuel Perry – stand-in for Tim Russ
Jerry Quinn – stand-in for Robert Duncan McNeill
Richard Sarstedt – stand-in for Robert Picardo and Francis Guinan
Jennifer Somers – stand-in for Jennifer Lien
Simon Stotler – stand-in for Ethan Phillips and Aaron Lustig
John Tampoya – stand-in for Garrett Wang
Unknown actor – stand-in for Henry Brown

References 
2304; 2361; 2367; ability; accusation; act of war; afternoon tea; anatomy; appeal; artificial Banea lifeform; atrium; attack maneuver kappa 010; autonomic response analysis; away team; ARA; bad habit;  (planet); Banea (species); Banea moon; Banea system; Banean dog; Banean Engineering Institute; Banean scanning device; Banean warship; ; bearing; bio scan analysis; blood; brain; brain damage; centimeter; chief medical officer; cloud burst; collimator; conviction; damage;  (runabout); defense perimeter; dehydration; directed energy weapons; disorientation; divorce; ; eclipse; engineering physicist; equation; evasive maneuvers; Federation; Flag of the Federation; formal charge; freedom; ; garden tool; generation; habit; heart; high orbit; husband; hydroxyproline; improper relations; intercostal space; Kappa 010; lethal injection; LN2 exhaust conduit; logic; low orbit; marob root tea; Maquis; medical facility; medicine; memory; memory engram; microscope; Milky Way Galaxy; mind; mind meld; Minister of Science; murder; navigational array; navigational deflector; nebula (unnamed); neodextramine solution; neural damage; neural implant; neural pathway; neurology; neurological analysis; Numiri; Numiri patrol vessel; pancreatic scan; phase emitter; phenomenon; professional cleaning crew; professor; punishment; red alert; regenerative shield; rib; risk; rolk; ; sculpture; slipper; small talk; smoking; ; stab wound; Starfleet; statue; stew; storm; subsystem; synaptic failure; ; Teluridian IV; telepathy; Thalmerite; transporting device; traveler; Type 8 shuttlecraft (unnamed); Vulcan; water

External links 
 
 
 
 

de:Die Augen des Toten
es:Ex Post Facto
fr:Ex Post Facto (épisode)
ja:VOY:殺された者の記憶
nl:Ex Post Facto
VOY episodes