New York Expands DNA Database . . . Again
New York has an appetite for expanding its forensic database; this new law represents the third time that the state has upped the ante in recent years. This trend, along with Governor Cuomo’s personal determination to expand the database, means that these new inclusion criterion were almost politically inevitable. An estimated 46,000 new profiles will be added to the database each year as a result of this new law.
One bright spot is that defendants and convicts will now have greater access to DNA testing to improve their ability to establish innocence. While this is surely welcome, it raises a broader question: will scientists have access to New York’s DNA database to assess claims regarding DNA forensics’ supposed infallibility?
Accumulating evidence suggests that there is a nontrivial risk that unknown DNA samples left at crime scenes and database profiles with known identities may match coincidentally. As I explained in a 2010 article in Science Progress:
The FBI and state law enforcement have largely responded to these rather peculiar findings by restricting outsiders’ access to these databases. Defendants’ and convicts’ greater access to forensic databases is a notable step forward, and other states should follow New York’s lead in this limited regard. But justice and transparency also demand greater access for independent auditors and scholars seeking to verify claims coming out of the databases.A recent examination of Arizona’s 65,493 database profiles led to a surprising result: 122 pairs matched at 9 loci, 20 pairs matched at 10, and two pairs of siblings matched at 11 and 12. There are also reports that other state databases are experiencing similar oddities. Illinois’ state databases reportedly showed that out of 220,000 profiles, 903 matched at 9 or more loci. And it has also been reported that Maryland’s database had 32 pairs of profiles matching at 9 loci and 3 matched at 13. These figures call into question the motivating claim behind DNA database searches—that profiles are unique and coincidental matches are extremely rare—which opens up the possibility for false convictions.