DA: DeSalvo DNA matches DNA found on body of Strangler's last victim

DNA test results show Albert DeSalvo "was the source of seminal fluid" found at the murder scene of Mary Sullivan in 1964, law-enforcement officials announced today.

Specifically, DNA specialists calculated the odds that a white male other than DeSalvo contributed the crime scene evidence at one in 220 billion. At the time Sullivan was killed, only about 3.2 billion human beings were alive on the planet, and only about 107 billion human beings have ever lived on the planet.

Officials had DeSalvo's remains dug up from a Peabody cemetery last week to obtain new samples after advances in DNA testing over the past couple of decades made it possible to sequence DNA found in Sullivan's apartment - and preserved for nearly 50 years.

The hunt for DNA samples also led officials to the DeSalvo family - a Boston Police fugitive detective trailed one of DeSalvo's nephews, waiting for him to discard something he had touched, which would let the detective grab the sample without requiring a search warrant. The detective eventually recovered a water bottle the nephew had drunk from and then thrown away, which officials say was used to confirm a link between males in the DeSalvo line and the Sullivan evidence.

Sullivan, at the time 19 and just four days after she had moved to Beacon Hill, was raped and strangled on Jan. 4, 1964. DeSalvo eventually confessed to her murder and that of other Strangler deaths, but later recanted. He was sentenced to life in prison on other charges and was murdered there in 1973.

At a press conference last week, officials emphasized the evidence applies only to the Sullivan case, because they have been unable to find enough DNA on which to conduct tests in the remaining cases.