K. K. HALL, Circuit Judge:
The State of Maryland appeals from the grant of a writ of habeas corpus issued by the district court setting aside the state court conviction of Roland Anderson because of misconduct on the part of the trial judge. We find that the trial judge committed error and we do not condone what he did. However, the overwhelming evidence supports the conviction, and therefore we find the error harmless beyond a reasonable doubt. Chapman v. California, 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967). Accordingly, we reverse.
Eleanor Davis was a sixty-two year old widow, living alone in Annapolis, Maryland. On the night of April 26, 1970, sometime between the hours of 10:00 p. m. and 2:00 a. m., she was raped and murdered in her bed. Her bloody and battered body was found the next morning by her adult son.
The day after the murder, the police brought Roland Anderson in for questioning. They did not arrest him then, but he agreed to be fingerprinted and he gave the police hair and saliva samples. He and his parents also consented to allow the police to search their home. During the search of the defendant’s bedroom, the officers found a pair of trousers with blood stains and seminal stains on them. When questioned, Anderson admitted having worn those pants on the night of the murder. Also, there were fingerprints and palmprints found inside Mrs. Davis’ bathroom window ledge and on her bathtub, which turned out to be the defendant’s. By May 8, the police had amassed enough evidence to consider Anderson a prime suspect, and they placed him under arrest.
Anderson signed a written confession after giving a detailed oral account of the crime. He related the following sequence of events: Having entered Mrs. Davis’ apartment through the bathroom window, he worked his way through the apartment looking for money. Mrs. Davis woke up while he was in her bedroom and recognized him. He knocked her unconscious with his fist. Then a “funny feeling” came over him and he raped her. When he remembered that she would be able to identify him, he decided to kill her. He searched around and found a hammer and a butcher knife. Returning to the bedroom, he beat her over the head with the hammer, and then, because she was still moaning, he slashed her left wrist with the knife. He left, taking the knife and the hammer, which he put into a brown paper bag and stuffed into the garbage can behind his house.
Item by item, the evidence corroborated the confession as follows:
1. Confession : He entered the apartment through the bathroom window.
Evidence : His fingerprints and palm-prints were found inside the bathroom window ledge and on the bathtub.
2. Confession : He searched through the apartment for money.
Evidence : Mrs. Davis was an impeccable housekeeper, yet her bureau drawers were found partially open, as if someone had been rummaging through them.
3. Confession: Mrs. Davis woke up and recognized him.
Evidence: They lived in the same neighborhood.
4. Confession: He knocked her unconscious.
Evidence : The state’s pathologist who testified at trial concluded that Mrs. Davis was raped while she was unconscious.
5. Confession : He raped Mrs. Davis.
Evidence : The autopsy report noted the presence of semen in Mrs. Davis’ vagina. Pubic hairs which were microscopically similar to Mrs. Davis’ were found on the trousers Anderson admitted having worn on the night of the crime. Seminal secretions found on the bedsheets and on Anderson’s clothing evidenced the présence of both of their blood groups. The last is a particularly telling point because Mrs. Davis had an uncommon blood type.
6. Confession : He hit Mrs. Davis over the head with the hammer.
Evidence: The pathologist testified that the murderer had smashed Mrs. Davis’'head with a blunt instrument causing gaping scalp wounds, numerous skull fractures, and bruising of the brain.
7. Confession: He slashed her left wrist to kill her.
Evidence: Although the pathologist testified that the head injuries alone would have been fatal, the direct cause of Mrs. Davis’ death was a deep cut on her left wrist.
8. Confession: He found a hammer and a knife, and took them with him when he left.
Evidence: Mrs. Davis’ son testified that a hammer was missing from his mother’s belongings.
In sum, the factual evidence matched the confession so exactly as to remove all reasonable possibility of coincidence.
Nevertheless, the defendant asserted that he was nowhere near the scene of the crime, but that he had been at Phyllis Cook’s house on the night of the murder. Ms. Cook and Clinton Roberts both confirmed his story. Roberts testified that he and Anderson had left for Cook’s house some time after 9:30 p.m. Although Cook did not know what time they had arrived, she said she knew Anderson had been at her house until 3:00 or 3:30 a. m.
After both sides had rested, the state’s attorney told the judge that he thought the alibi witnesses had lied. The judge called Cook and Roberts into his chambers and admonished them about the consequences of perjury, whereupon they both agreed to change their stories. The judge then reconvened court and told the jury that the two alibi witnesses had lied in their earlier testimony and wanted to revise their statements. As the witnesses took the stand again, the judge cautioned them that they were being given one last chance to tell the truth. Roberts then admitted that he could have been mistaken about the time he left Anderson’s neighborhood that evening, and conceded that it could have been as late as 10:30 or 11:00 p. m. Cook, in turn, acknowledged that she could not be sure if Anderson had been at her house for the entire time between 1:00 a. m. and 3:00 a. m.
The jury found Anderson guilty. We find no reason to question the validity of that verdict.
Anderson tried to establish an alibi with two witnesses who from the start were not positive about the exact amount of time they had spent with him. All the later testimony did was to emphasize how vague their memories actually were. Furthermore, even if Cook and Roberts had never changed their stories, Anderson’s alibi defense would have been unavailing. As we outlined above, the evidence corroborated his confession in every detail. Only the murderer could have given as exact an account of the crime as Anderson did.
In the past, courts have gone to extraordinary lengths in the name of liberty to free guilty people on technicalities. Under the facts of this case, we refuse to adopt that practice. Roland Anderson was found guilty by a jury of his peers. That conviction is supported by a large body of evidence and cannot be impugned by the trial judge’s error.
We have considered the other issues Anderson has raised and we find them to be without merit. Accordingly, we reverse the decision of the district court and hold that the petition for a writ of habeas corpus is denied.
REVERSED.
. Anderson was fifteen years old at the time of the crime. Before questioning him, a police officer read him his Miranda rights and explained them to him in the presence of his parents. During the explanation, the officer stopped frequently and another officer asked them if they understood what was being said. Once the defendant had been fully advised of his rights, he and his parents signed a waiver of rights form.
After a couple of hours of questioning, he confessed to the crime. The officer then prepared a written confession and Anderson signed it.
At trial, Anderson tried to disavow the written confession, claiming that he had only a seventh grade education and could not read what he was signing. His argument has no merit. The questioning agent testified about the oral statement in which the defendant had related the details of the murder. The signed confession was merely that statement reduced to writing. Anderson was able to tell about the enme even if he could not read many of his words once they were written down.
. Anderson said that he had gone into Mrs. Davis’ apartment through the bathroom window about three months earlier to help her get in when she had locked her keys inside. He said that at that time Mrs. Davis had told him that she was so forgetful about her keys that she had to keep her bathroom window unlocked.
. These items were never recovered.
. In disputing his confession, Anderson asserted that his fingerprints were in Mrs. Davis’ bathroom because he had gone in through the bathroom window to help her get into her apartment when she had locked herself out about three months earlier. This explanation is patently incredible. No juror could believe that the defendant’s fingerprints would have remained on Mrs. Davis’ bathtub for three months.
. Mrs. Davis belonged to blood group B; Anderson belongs to blood group A. According to expert testimony adduced at trial, evidence of a person’s blood type can be found in body secretions such as saliva, semen, and vaginal fluids. Thus, the presence of both types in the secretions is easily explained: Anderson’s semen could have contributed the type A factor; Mrs. Davis’ vaginal discharge could have contributed the type B factor.
. An expert at trial testified that only 10% of the population belongs to blood group B.
. The judge said,
Mr. Foreman, ladies and gentlemen of the jury at the conclusion of this case two of the witnesses who testified have indicated to the Court that they told an untruth in their testimony and desire an opportunity to correct that before you ladies and gentlemen before this case concludes. As a matter of law, the Court must afford a witness an opportunity to purge himself or herself of perjury. For that purpose we are recalling these two witnesses to the stand to give them an opportunity to revise their stories to what they are now saying is the correct testimony.
. To Ms. Cook, in the presence of the jury, the judge said,
You have indicated to the Court that a portion of the testimony that you previously gave under oath in this case was false. The Court now affords you an opportunity to correct that testimony by telling the" truth and to purge yourself of the perjury you have committed. This is the last chance you will be given in this trial to tell the truth.
Before Roberts took the stand again, the judge spoke with him, in front of the jury, as follows:
Judge Bowen: At the conclusion of the testimony in this case you indicated to the Court that some portions of the testimony you had given before this jury were false. You asked the Court for an opportunity to purge yourself of this crime by being afforded an opportunity to tell the truth to the jury. This is your opportunity to tell the truth. It is the last one you are going to get in this trial. A. Yes sir.
Judge Bowen: You better make good use of it.
. Compare e.g., United States v. Bates, 468 F.2d 1252 (5th Cir. 1972). In Bates, a key witness for the prosecution completely changed his testimony after he had been accused of perjury. Unlike that case, the altered testimony here could better be characterized as a clarification.
. Anderson claims ineffective assistance of counsel. The only arguable instance of ineffective assistance is counsel’s failure to object when the judge commented to the jury about the alibi witnesses’ testimony. However, since we hold those acts to have been harmless error, counsel’s failure to object can not be faulted.