Nightly News | July 11, 2013
>>> at long last, a big break tonight in the murder case that received national attention as it gripped the city of boston half a century ago. he was known as the boston strangler and tonight it appears science may have finally caught up with him. we get the story tonight from nbc's katy tur.
>> reporter: 50 years ago, boston was held hostage.
>> evidence so far is skimpy.
>> reporter: 11 women, most sexually assaulted, found dead in their homes.
>> there is fear in boston .
>> never really an end to the story. always lingering in the air for several years. who was it? still out there?
>> reporter: albert de salvo confessed, but doubts surrounded his claims. he tdied in prison in 1973 .
>> a genuine murder mystery and the reopening of the boston strangler .
>> reporter: they hoped dna would prove de salvo did it. it did not. today, new advanced testing will prove he was sullivan 's killer.
>> these results are unprecedented in the history of this case. for the first time ever, law enforcement has a piece of evidence to test against a suspect.
>> reporter: the suffolk d.a. said they could take dna evidence from 50 years ago, collected right here at mary sullivan 's apartment and cross reference it with dna with a member of sullivan 's family, and that's how they found a match. police are 99.9% positive, but will exhume de salvo's body to be sure. this is the lawyer that represents de salvo's family.
>> just because you find dna on a person's body, doesn't mean that they murdered that person.
>> my aunt, a 19-year-old girl, heinously murdered in 1964 . people