Crime Library: Criminal Minds and Methods

The Capture of Serial Killer Arohn Kee

DNA Testing

DNA testing was first used in a criminal investigation in England in 1986, and it was in limited use in the United States by the following year. But it was still a nascent forensic science in 1991, when young Paola was murdered. That had changed in 1998. By then, DNA was widely regarded as the most important investigatory breakthrough since the fingerprint. And the East Harlem cases would bear that out. Tissue samples had been collected over the years from rape and murder suspects, and prosecutors ordered DNA tests on at least five men suspected in the attacks, including two who had been picked out of police lineups by rape victims.

In the 1990s, there was a limited archive of DNA samples on file because routine testing of felons had not yet begun on a large scale. But a key development in the East Harlem cases came in the fall of 1998 when New York police criminalists compared semen evidence from the Rasheeda Washington murder and two other rapes in that neighborhood. The tests determined that the same perpetrator was responsible for the three crimes. Detectives were finally certain that a serial criminal was preying upon Harlem teenagers, and the police brass formed a small task force of detectives to find the man.