Conley said 11 murders have been attributed to DeSalvo -- who confessed to the killings -- including Sullivan . NEW : Mary Sullivan `` outraged , disgusted `` by secret DNA collection , their attorney says . NEW : ` ` We have offered them DNA as recently as 1973 , '' the attorney says . DNA from a relative links DeSalvos to the last DeSalvo victim , Mary Sullivan . Strangler was never charged in the killings and was stabbed to death in 1973 .
NEW : Mary Sullivan `` outraged , disgusted `` by secret DNA collection , their attorney says . NEW : `` We have offered them DNA as recently as 1973 , '' the attorney says . DNA from a relative links DeSalvos to the last DeSalvo victim , Mary Sullivan . Strangler was never charged in the killings and was stabbed to death in 1973 .