Who Was the Boston Strangler? The True Story Behind Keira Knightley's Film

The case of the Boston Strangler was one that confounded authorities for 50 years, and it is now the subject of a new film starring Keira Knightley.

Hulu's true crime drama, simply titled Boston Strangler, sees Knightley portray Loretta McLaughlin, the first journalist to connect the Boston Strangler murders. With the help of colleague Jean Cole (Carrie Coon), McLaughlin began to investigate the tragic deaths that were happening across the city in a bid to uncover the truth.

The real identity of the Boston Strangler is a subject that has been of interest for decades. Here is everything that we know.

Who Was the Boston Strangler? The True Story Behind Keira Knightley's Film

Keira Knightley and Albert DeSalvo
In this composite image is Keira Knightley (R) as Loretta McLaughlin in Hulu film "Boston Strangler" and a picture of self-admitted Boston Strangler Albert DeSalvo (L). 20th Century Studios/Getty Images

Between 1962 and 1964, the Boston Strangler raped and killed 11 women across the city. The serial killer's victims were aged between 19 and 85. His last known victim was Mary Sullivan, who was killed in January 1964.

The Boston Strangler would sexually assault his victims and then murder them, he became known by the moniker because of how he killed his victims and then left the rope or cord he used he'd used tied in a bow.

At the time, the police struggled to identify exactly who the criminal was. In the end it was a confession from Albert DeSalvo while in prison that brought him to their attention.

DeSalvo had been arrested by police after raping a woman on October 27, 1964. After the assault the woman was able to positively identify him to authorities which led to his arrest.

Per History, DeSalvo confessed to the murders while speaking with his cellmate George Nasser, who in turn told his attorney, F. Lee Bailey. The lawyer took on DeSalvo as a client and made a deal with prosecutors that meant he was not charged or convicted for the Boston Strangler murders. DeSalvo later recanted his confession to the killings.

DeSalvo was instead given a life sentence for sexually assaulting multiple women over a period of two years. On November 26, 1973 he was found dead in his cell after being stabbed in Walpole State Prison.

The fact that DeSalvo was never convicted for the Boston Strangler murders led some to believe he was not the one responsible, however in 2013 DNA evidence was used to prove with a 99.9 percent certainty that DeSalvo was the Boston Strangler according to an ABC News report.

Police used a water bottle discarded by DeSalvo's nephew Tim DeSalvo to get the DNA evidence they needed to compare to samples that had been preserved from Sullivan's murder, the media outlet reported.

At the time, Suffolk County District Attorney Dan Conley said: "This is good evidence. This is strong evidence. This is reliable evidence. But there can be no doubt."

Per a report from the U.S. Department of Justice, Boston authorities exhumed DeSalvo's body in July 2013 and compared his DNA to the evidence that remained from the Sullivan case.

A match was found and so DeSalvo was positively identified as the person who raped and killed Sullivan.

Boston Strangler is available to watch on Hulu now.