DNA Analysis Case Study: Boston Strangler

The Boston Strangler's reign of terror lasted from 1962 to 1964, during which it was believed he raped and killed 11 single women.

His operating area was very large and widespread, causing difficulty in linking the crimes to one another and to a single assailant.

The victims were raped and strangled to death. The ligature used to strangle the victims was tied in a large ornamental bow around their neck.

A murderer by many names

Albert DeSalvo started his criminal life with lower-level sex offences. He would go door-to-door looking for young women. When he found one, he would introduce himself as a talent scout from a modelling agency in search of new models.

If the women expressed interest, he would ask to get their measurements. When he took the measurements, he would fondle the women as he did. He thus became known as the "Measuring Man".

In 1960, Albert DeSalvo was caught breaking into a home and arrested. He confessed to being the Measuring Man and served 11 months of his 18-month sentence before being released based on good behaviour.

After his release, he began his new crime spree throughout the Massachusetts, and New Hampshire areas. Dressed in green, he broke into over 400 houses and sexually assaulted over 300 women. This earned him the name the "Green Man”.

While searching for the Green Man, the homicide detectives in Boston continued searching for the so called "Boston Strangler”.

In 1964, a victim of the Green Man came forward to police stating a man posing as a detective entered her house and assaulted her. Through her description, DeSalvo was identified as the assailant. When DeSalvo's picture was published in newspapers, many more women came forward identifying him as their attacker.

He was arrested on a rape charge and sent for psychiatric observation. Here, DeSalvo confessed to his attorney that he was the Boston Strangler. He described the murders in extreme detail, leading the detectives to conclude he was the killer.

Although he confessed, no physical evidence was found to link DeSalvo to the murders. The Strangler's one surviving victim was brought to the prison to see if she could identify her attacker. She did not identify DeSalvo as her attacker.

Because there was no physical evidence and no witnesses identified DeSalvo as their attacker, he was not tried for the Boston Strangler. He was, however, sent to prison for the sexual assaults from the Green Man case. No one was ever tried for the Boston Strangler murders.

DeSalvo was killed in prison in 1973.

Revealing the truth through DNA analysis

Recovered from a maroon blanket retrieved from the murder scene of 19-year-old Mary Sullivan was a seminal fluid stain. Six samples of this DNA evidence were taken and preserved, awaiting advances in DNA technology.

In 2013, the DNA collected was compared to Albert DeSalvo's nephew, Tim DeSalvo, showing a familial match. After this was proven, Albert DeSalvo's body was exhumed.

DNA was extracted from some of his teeth and his femur and tested against the DNA from the stain. It was a 99.9% match.

This meant that the case of Mary Sullivan's murder was closed but the mystery of the Boston Strangler remains open to speculation.

Many investigators believed DeSalvo to be responsible for the other Boston Strangler murders following the conclusion of Mary Sullivan's case.

Do you think DeSalvo was responsible for the other Boston Strangler murders?