Albert DeSalvo F. Conley said he expected investigators to find an exact match when the evidence is compared with his DNA. On July 19, 2013, Suffolk County DA Daniel F. Conley, Mass. Attorney General Martha Coakley and Boston Police Commissioner Edward F. Davis announced that DNA test results proved DeSalvo was the source of seminal fluid recovered at the scene of Sullivan's 1964 murder. Though DeSalvo was conclusively linked to Mary Sullivan's murder, doubts remain as to whether he committed all of the Boston Strangler homicides — and whether another killer could still be at large. When he confessed, people who knew
Serial killer killers are commonly categorized as murdering men for material gain, usually being emotionally close to their victims, and generally needing to have a relationship with the victim, hence the traditional cultural image of the "black widow." In describing murderer Stacey Castor, forensic psychiatrist James Knoll offered a psychological perspective on what defines a "black widow" type. In simple terms, he described it as a woman who kills two or more husbands or lovers for material gain. Though Castor was not officially defined as a serial killer, it is likely that she would have killed again. One "analysis of 86 female