Defector
A defector was a type of renegade who changed his allegiance from one government or organization to another. 

In 2155, Susan Khouri tried to defect from Terra Prime to save Elizabeth, but was killed before she could leave the movement. ()

In 2257, L'Rell told Katrina Cornwell that she wished to defect to the Federation in exchange for helping Cornwell escape from her cell on the Sarcophagus. However, the offer was part of a ruse for L'Rell to board the . ()

In 2258 of the alternate reality, upon learning that "John Harrison"'s destination was Qo'noS, Admiral  asked whether he was defecting.  expressed his uncertainty about the possibility. ()

Romulan Admiral Alidar Jarok defected to the Federation in 2366. He had done so believing that the Romulan government was establishing a secret base on Nelvana III as a prelude to an invasion. He believed that the war which would follow had the potential to destroy the Romulan Empire. He defected in order to provide the Federation with the information to prevent such a war by destroying the Nelvana III base before it became operational. He did not realize that the information he had was disinformation fed to him by his government, which suspected that he might defect. Upon realizing this, he committed suicide. ()

One possible explanation for the sighting of Spock on Romulus in 2368 was that he had defected. Sarek vehemently protested against this possibility and was later proven to be correct. ()

In 2349, Ensign DeSeve of Starfleet defected to the Romulans. He believed that the Romulans had clear moral values and an absolute certainty about what was right and wrong. As the years passed, he grew disillusioned with such a philosophy and returned to the Federation in 2369 to convey a message from the Romulan underground movement and assist in the defection of M'ret and two of his aides. ()

Ro Laren defected to the Maquis. ()

In 2371, Seska defected from the  to the Kazon-Nistrim. ()

In 2374, a drunk Quark initially misremembered the word deflector as defector, briefly making the Deep Space 9 resistance movement believe that the self-replicating mines blocking the Bajoran wormhole were going to be disabled with the help of a defector. ()

Later that year, Lasaran tried to defect from the Dominion to the Federation on Soukara, but was killed because Worf didn't pick him up to be transported to Federation space. ()

In 2375, Weyoun 6 brought Odo to a barren moon in Cardassian space and announced his intention to defect. Weyoun stated that he felt the Dominion's war against the Federation and its allies was wrong, and holding such a view put him at risk of being killed. He offered Odo all the information he had on the Dominion in exchange for being extracted to the Federation. Though Odo did attempt to do that, Jem'Hadar forces dispatched by Damar and the seventh clone of Weyoun prevented it. Weyoun 6 eventually made use of his termination implant to prevent Odo's death. ()

Also in 2375, Kashyk of the Devore Imperium appeared to defect to the starship  in the Delta Quadrant in order to assist Captain Janeway with transporting her telepathic crew members and passengers through his government's space. His defection, however, was a ruse designed to expose and capture the telepaths and Voyager. Kashyk, however, was himself double-crossed by Janeway, and his ruse failed. ()

See also 
 Deserter

External link
 

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Illegal occupations