Fewer than 20 percent of property crimes in New York City are solved. The New York Times says that is partly because evidence and witnesses are hard to come by, and partly because most manpower and money is devoted to catching violent criminals. DNA testing is routinely done only in homicides, rapes, and the most serious assaults.
Now the chief medical examiner’s office plans a new lab to test hundreds of DNA samples a day from nearly every crime scene, including burglarized homes and stolen cars. The lab will use DNA samples previously considered too minuscule to collect, like skin cells left in a smudged fingerprint, and match them against databases of convicted felons, suspects, and DNA profiles from crime scenes and rape kits.
The prospect offers a powerful tool to catch criminals so elusive that many New Yorkers do not even bother to report burglaries. If perpetrators tend to move from nonviolent to violent crimes, the tests could contribute to public safety. “It extends to a whole universe of crimes that other technology can’t touch,” said Dr. Charles Hirsch, chief medical examiner. “And we know there are crossover criminals, that burglars become rapists. The impact has a big ripple effect.”
There are no national standards for tests on such small samples, called low copy number DNA analysis, and their admissibility in court has not been widely tested. Using DNA to solve property crimes is catching on: samples of DNA taken from burglaries in Miami have yielded a high number of matches in the database.
The New York lab plans to use robots to test 800 DNA samples a day. Some caution that the method is vulnerable to contamination or mistaken conclusions. “You get spurious results,” said Lawrence Kobilinsky of John Jay College of Criminal Justice. “You have to interpret everything very carefully….low copy number has been looked at very carefully by the F.B.I., and I think that in general their attitude is, this is not ready for prime time.” City forensic scientists counter that they have done extensive work to validate their techniques.