The DNA of Albert DeSalvo, who confessed and then recanted his confession to the Boston Strangler murders, matches a semen sample from a 1964 crime scene, authorities said after exhuming his body for testing.
The results mark the first time DeSalvo has been scientifically tied to the 1964 slaying of Mary Sullivan, who is believed to be the Boston Strangler’s 11th and final victim, according to a statement e-mailed today by Massachusetts Attorney General Martha Coakley and Suffolk County District Attorney Daniel Conley.
“This leaves no doubt that Albert DeSalvo was responsible for the brutal murder of Mary Sullivan, and most likely that he was responsible for the horrific murders of the other women he confessed to killing,” Coakley said in the statement.
DeSalvo was never charged in any of the killings after recanting his post-arrest confession to about a dozen murders because prosecutors lacked other evidence. In 1973 he was killed in prison, where he was serving a life sentence for a non-related sexual assault.
Scientists specializing in DNA analysis said the odds the semen belonged to a white male other than DeSalvo were about one in 220 billion, according to the statement. At the time Sullivan was killed, there were about 3.2 billion people on the planet.
Boston police won court approval to unearth DeSalvo’s body after DNA recovered from Sullivan’s body and stored for almost 50 years was found to match closely DNA of one of DeSalvo’s surviving male relatives, authorities said on July 11.
Boston authorities waited for years for DNA sampling technology to advance sufficiently before sending two samples from Sullivan’s murder scene to two testing companies.
After a sample was identified, Boston police needed to compare it to DNA from one of DeSalvo’s male family members because traits are inherited.
Police did not ask the family to supply a sample. Instead, a surveillance expert followed one of DeSalvo’s nephews until he discarded a water bottle, which was collected and tested, police said. A match was made, ruling out 99.9 percent of other males, according to police.
Authorities then won a court order allowing them to exhume DeSalvo’s body from a grave in Peabody, Massachusetts.
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