( CNN ) -- The remains of a man who confessed to being the Boston Strangler were exhumed Friday by authorities working to connect him to the January 1964 killing of Mary Sullivan , the last of 11 women believed killed by the serial killer . New DNA tests on a secret sample collected from a relative of suspect Albert DeSalvo triggered the exhumation after authorities said there was a `` a familial match '' with genetic material preserved in the killing of 19-year-old Sullivan , Suffolk County District Attorney Dan Conley said Thursday . Authorities made the match through DNA taken from a water bottle thrown away by DeSalvo 's nephew , he said . DeSalvo 's remains were removed from Puritan Lawn Memorial Park in Peabody , north of Boston , to the state medical examiner 's office , where DNA tests will be performed . Authorities said they believe the results will come back quickly , perhaps in a few days . The Strangler killings terrorized Boston from mid-1962 to early 1964 . Conley said 11 killings have been attributed to DeSalvo -- who confessed to the deaths -- including Sullivan 's . DeSalvo also confessed to two additional killings , which were not suspected Strangler victims . City of Fear : Photos from the Boston strangler era , 1963 . DeSalvo was never charged with the killings . He was stabbed to death in 1973 while serving a life prison term for unrelated rapes . The news has convinced Sullivan 's nephew , Casey Sherman , who wrote a 2001 book in which he argued that another man may have been behind the Strangler killings . He said Thursday that he was surprised his aunt 's slaying was still being investigated . `` It 's taken 49 years for police to legitimately say they got their man , and they 'll probably be able to say that very soon , '' Sherman said . But a lawyer for the DeSalvos told CNN the family was `` outraged , disgusted and offended '' by the decision to secretly take a DNA sample of one of its members , a move she called `` unnecessary and creepy . '' `` They feel victimized by this process , '' said the attorney , Elaine Whitfield Sharp . `` This was an unwarranted invasion of privacy by a government agency . We have offered them DNA as recently as last year . There was no reason to sneak around to get it . '' Scientists tried several times in the late 1990s and early 2000s to isolate DNA evidence from semen found in Sullivan 's body and on a blanket , authorities said . They resumed their efforts last year , after a laboratory successfully salvaged DNA from decades-old material , and found what they believe is the unique genetic profile of Sullivan 's killer . Serial Killers : Fast Facts . Despite an exhaustive search , investigators found no usable samples of DeSalvo 's DNA to compare with the material from the crime scene . So Boston Police Commissioner Ed Davis said he had a detective from the police department 's fugitive squad shadow DeSalvo relatives until he spotted one of the suspect 's nephews throwing away a water bottle . The nephew was working at an outdoor construction site when he threw away the plastic bottle , which was retrieved by plainclothes investigators , according to a law enforcement source who spoke on condition of anonymity . Conley said authorities did n't ask the DeSalvo family for their cooperation , but he defended the secret collection of their DNA as `` a fair and legal and ethical method . '' DeSalvo 's brother , Richard DeSalvo , offered blood and saliva samples in hopes of proving his brother 's innocence in 2001 . Those tests had been unable to find a match between DeSalvo family DNA and the killings , but Conley discounted them Thursday because they were n't conducted by law enforcement . CNN 's Matt Smith and Bob Crowley contributed to this report .
Albert DeSalvo confessed to being the Boston Strangler . Score: 6 He was never charged in those crimes , and he was killed in prison in 1973 . Authorities believe they have linked DeSalvo to one killing .