DeSalvo was born in Chelsea, Massachusetts, to Frank and Charlotte DeSalvo. His father was a violent alcoholic, who at one point knocked out all of his wife’s teeth and bent her fingers back until they broke. DeSalvo tortured animals as a child, and began shoplifting and stealing in early adolescence, frequently crossing paths with the law.  In November 1943, the 12-year-old DeSalvo was first arrested for battery and robbery. In December of the same year he was sent to the Lyman School for Boys. In October 1944, he was paroled and started working as a delivery boy. In August 1946, he returned to the Lyman School for stealing an automobile. After completing his second sentence, DeSalvo joined the Army. He was honorably discharged after his first tour of duty. He re-enlisted and, in spite of being tried in a court-martial, DeSalvo was again honorably discharged. DeSalvo served with the 2nd Squadron, 14th Armored Cavalry Regiment. Pictures of DeSalvo being arrested on Saturday February 25, 1967 show him in US Navy Dress Blue Uniform with Petty Officer 3rd insignia on his sleeve.

Between June 14, 1962, and January 4, 1964, 13 single women between the ages of 19 and 85 were murdered in the Boston area; they were eventually tied to the Boston Strangler. Most of the women were sexually assaulted in their apartments, and then strangled with articles of clothing. The eldest victim died of a heart attack. Two others were stabbed to death, one of whom was also badly beaten. Without any sign of forced entry into their dwellings, the women were assumed to have either known their killer or voluntarily allowed him into their homes. The police were not convinced that all of these murders were the work of a single individual, especially because of the wide gap in the victims’ ages; much of the public, on the other hand, readily accepted that the crimes were committed by one person.

In the fall of 1964, in addition to the Strangler murders, the police were also trying to solve a series of rapes committed by a man who had been dubbed the “Measuring Man” or the “Green Man”. On October 27, 1964, a stranger entered a young woman’s home in East Cambridge posing as a detective. He tied his victim to her bed, proceeded to sexually assault her, and suddenly left, saying “I’m sorry” as he went. The woman’s description led police to identify the assailant as DeSalvo and when his photo was published, many women identified him as the man who had assaulted them. Earlier on October 27, DeSalvo had posed as a motorist with car trouble and attempted to enter a home in Bridgewater, Massachusetts. The owner of the home, future Brockton Police Chief Richard Sproles, became suspicious and ultimately fired a shotgun at DeSalvo.

Under arrest for his role in the “Green Man” rapes, DeSalvo was not suspected of being involved with the murders. Only after he was charged with rape did he give a detailed confession of his activities as the Boston Strangler, both under hypnosis induced by William Joseph Bryan and also without hypnosis during interviews with Assistant Attorney General John Bottomly. He initially confessed to fellow inmate George Nassar, who then notified his attorney, F. Lee Bailey. Bailey took DeSalvo’s case. Though there were some inconsistencies, DeSalvo was able to cite details which had not been made public. However, there was no physical evidence to substantiate his confession. As such, he stood trial for earlier, unrelated crimes of robbery and sexual offenses. Bailey brought up the confession to the murders as part of his client’s history at the trial as part of an insanity defense, but it was ruled as inadmissible by the judge.

For his 1967 trial, DeSalvo was mentally evaluated by Dr. Harry Kozol, also of Eugene O’Neill and Patty Hearst fame. Bailey engaged a plea bargain to lock in his client’s guilt in exchange for taking the death penalty off of the table and also to preserve the possibility of an eventual insanity verdict. Bailey was angered by the jury’s decision to put DeSalvo in prison for life: “My goal was to see the Strangler wind up in a hospital, where doctors could try to find out what made him kill. Society is deprived of a study that might help deter other mass killers who lived among us, waiting for the trigger to go off inside them.”

DeSalvo was sentenced to life in prison in 1967. In February of that year, he escaped with two fellow inmates from Bridgewater State Hospital, triggering a full-scale manhunt. A note was found on his bunk addressed to the superintendent. In it, DeSalvo stated he had escaped to focus attention on the conditions in the hospital and his own situation. Three days after the escape he called his lawyer to turn himself in. His lawyer then sent the police to re-arrest him in Lynn, Massachusetts. Following the escape, he was transferred to the maximum security prison known at the time as Walpole, where he later recanted his Strangler confessions. On November 25, 1973, he was found stabbed to death in the prison infirmary. Robert Wilson, who was associated with the Winter Hill Gang, was tried for DeSalvo’s murder but the trial ended in a hung jury—no one was ever convicted for his murder. Walpole inmates continue to say nothing about the crime and it today remains unsolved.

DeSalvo’s papers are housed in the Lloyd Sealy Library Special Collections at John Jay College of Criminal Justice in New York City. His papers include his correspondence, mainly with the members of the Bailey family, and gifts sent to the Baileys of jewelery and leatherwork crafted by DeSalvo while in prison.