Boston police identified a dead man as the assailant in the 1973 murder and sexual assault of a 24-year-old woman in her Beacon Hill apartment, officials said Thursday.
Police Commissioner Edward F. Davis and Suffolk District Attorney Daniel F. Conley announced the break in the cold case and identified Michael Sumpter Thursday as the man who raped and strangled 24-year-old Mary Lee McClain on Dec. 12, 1973.
Sumpter died of cancer in 2001 while serving a 15-to-20-year sentence for another crime, the rape of a 21-year-old woman in her Beacon Street home in 1975, officials said in a statement.
He was connected to the slaying based on DNA evidence techniques unavailable at the time of the crime, officials said.
The brutal attack on McClain is the second slaying from the 1970s that authorities have linked to Sumpter. In 2010, DNA evidence connected him to the 1972 rape and killing of Ellen Rutchick, 23, in her Beacon Street residence.
He is also believed to have raped a 21-year-old woman in a Marlborough Street apartment in 1985. In 2002, Sumpter was was linked to that assault from DNA evidence he was ordered to provide following his conviction for the 1975 rape.
Police concluded at the time of McClain’s slaying that she was killed by an unknown person who broke into her apartment on Mount Vernon Street. Boston police collected evidence and interviewed several people, but were unable to connect the rape and killing to Sumpter until a federal grant provided the money to launch a cold case investigation in May, officials said.
“This is a story about an old case and new technology, but also a story about hope and perseverance,” Conley said in the statement. “Mary’s family never lost their faith that her murder would be solved. Investigators stored the crucial evidence for decades under laboratory conditions, even after the case went cold.’’
He added: “When a new team brought the latest science to the table, that hope and perseverance paid off with a positive identification of her killer. After all these years, we hope this news and the finality of the suspect’s death to cancer can provide them some sense of closure.”
Police and prosecutors have found no evidence to suggest that McClain knew Sumpter, who had a documented history of violence against women living in Beacon HIll and in the Back Bay, officials said. If he were alive today, authorities said he would be charged with murder in the McClain case.
“Our dedicated detectives and our crime lab analysts worked tirelessly on this case,” Davis said. “They never gave up, leaving no stone unturned to provide the family with answers. We hope this information gives them some peace.”
Sumpter was identified as a suspect in all three cases after evidence from the crime scenes was submitted to the Boston Police Crime Laboratory and then to the FBI’s Combined DNA Index System, a database of DNA samples from unsolved crimes and known offenders.
Last month, similar techniques led to the conviction of serial rapist Charles H. Brook Jr. for the 1989 murder of Zahia Salem, 87, in her South End home, authorities said. As with Sumpter, Brook was ordered to submit a DNA sample because of his prior convictions.
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