Massachusetts authorities have linked the 1964 murder of Mary Sullivan to self-professed “Boston Strangler” Albert DeSalvo through DNA evidence that was not available at the time, Suffolk County District Attorney Dan Conley said during a Thursday press conference announcing a “major development” in the case.
DeSalvo confessed to raping and killing Sullivan, but authorities had their doubts as to the authenticity of DeSalvo’s confession to being the “Boston Strangler” who terrorized women in Beantown in the 1960s, because of inconsistencies. The suspect, who was imprisoned on sexual assault charges and not the Strangler murders, confessed in prison. He was murdered while in prison in 1974.
“That confession has been the subject of skepticism and controversy almost from the moment it was given,” Conley said. There was no physical evidence linking DeSalvo to the Sullivan murder “until today.”
Conley said DNA from the crime scene was matched with a suspect in Sullivan’s murder.
“That suspect is Albert DeSalvo,” Conley said, adding that his body is set to be exhumed “to prove DeSalvo’s guilt once and for all.”
Investigators also matched seminal fluid containing DNA from Sullivan’s body and the blanket the 19-year-old victim’s body was wrapped in with a water bottle recently discarded by a nephew of DeSalvo’s. Stains on the blanket contained a mixture of two DNA profiles – one of Sullivan’s and another of an unidentified male.
“There can be no doubt that the male DNA belongs to the individual who murdered and raped Mary Sullivan,” Conley said, explaining that male descendants of the same father basically have the same Y chromosome.
The Boston Strangler was believed to have raped and murdered 13 single women in Boston between 1962 and 1964. The victims ranged in age from 19 to 85 and Sullivan was believed to be the last victim, according to Massachusetts Attorney General Martha Coakley.
She said the new DNA evidence in the Sullivan murder “may have solved one of the nation’s most notorious serial killings.”
Conley said the developments in Sullivan’s murder case have no bearing on the other homicides attributed to the Boston Strangler.
“But we do believe we stand on the threshold regarding unprecedented certainty regarding Mary Sullivan’s murder,” he said.
Boston Police Chief Ed Davis said officers followed members of the DeSalvo family until police could find a discarded object that could be used to obtain a DNA sample. A nephew of DeSalvo’s was seen throwing out a water battle, which led to the development in the case.
“That water bottle was tested and the match came back,” Davis said.
DNA evidence was not known at the time of the Boston Stangler murders. Attempts were made in the 1990s to extract DNA from seminal fluid recovered from Sullivan’s body and the blanket, but a crime lab was unable to extract a DNA profile from the samples.
Sullivan’s body was tested in 2000 and 2001, but a profile again couldn’t be extracted.
Don Hayes, director of the Crime Laboratory Unit of the Boston Police Department, decided at that point to halt all further testing on evidence in the Sullivan murder until technological advances in DNA testing could be useful enough. Each additional test would mean the erosion of DNA evidence, and Conley credited Hayes in part for Thursday’s development.