Although Albert DeSalvo, the purported “Boston Strangler,” was suspected in Sullivan’s rape and murder in January 1964, the case remained unsolved until after DeSalvo’s death in prison in 1973. In 2009 and 2012, the city of Boston received competitive grants under NIJ’s DNA program. The Boston Police Department’s cold case squad decided to use some of the NIJ funding to test DNA from a nephew of DeSalvo’s in order to seek a match with seminal fluid that had been found on Sullivan’s body and a blanket at the crime scene; they got a match. The match was possible because of years of NIJ DNA funding of research on Y-STRs. Y-chromosome DNA profiles come from fathers who pass their Y-STR DNA profiles to their male offspring. Barring a mutation, the profiles remain unchanged. Every male in a paternal lineage has the same Y-STR DNA profile. This includes fathers, sons, brothers, uncles, nephews, and a wider group of male relatives, even to third and fourth cousins. Boston authorities went a step further and exhumed DeSalvo’s body in July 2013, so they could conduct a confirmatory test using a DNA sample directly from DeSalvo. DNA extracted from a femur and three teeth yielded a match, leaving no doubt that DeSalvo had raped and murdered Mary Sullivan.