As we continue to expand the national DNA database through broader sampling criteria in a growing number of states, the debate grows on the ethics of DNA collection and how the DNA database is administered. When DNA samples are taken at the time of arrest rather than at conviction (as they are in 18 of the 21 states that collect DNA samples), the inevitable question follows of how to deal with the DNA profiles of suspects proven to be innocent.

While each state has its own laws concerning the collection of DNA and its expungement upon acquittal, there are some universal rules for states wanting to contribute to the Combined DNA Index System (CODIS). This includes a requirement that records of the innocent must be expunged. However, only 43% of states that collect DNA samples automatically expunge the data upon acquittal. In most states the suspect must request that their record be expunged from the database.

Britain was recently forced to address this issue when the European Court of Human Rights ruled its policy of collecting DNA from all suspects at the time of arrest and retaining those records regardless of the innocence or guilt of the suspect to be a breach of privacy. The British DNA database, which profiled about 8% of the population (compared to a mere .5% in the U.S.) was believed to contain profiles of as many as 800,000 innocent people. The British government expunged hundreds of thousands of records in response to the Court’s ruling.

Critics of the national DNA database claim that collecting DNA at the time of arrest, in particular, is a violation of privacy and an assumption of guilt. However, proponents argue that it is a simple extension of fingerprinting as a means for identification.

The genetic markers used by CODIS are unique to each individual, but do not indicate height, appearance, race, or sex. Furthermore, unlike fingerprints, CODIS can only be used for law enforcement purposes and cannot be cross-referenced for employment purposes.

Others argue that collecting DNA at the time of arrest is just a matter of logistics. It is more efficient to collect the sample while collecting fingerprints and processing the suspect than to collect a DNA sample later. Some states collect the sample at arrest but process it post-conviction.

The drawbacks of expungement are less often reported, but can be significant to law enforcement. The most obvious is the increased chance of finding a match when a larger portion of the population is in the database. Expungement also takes its toll on the DNA processing backlog. Some criminals have lengthy arrest records, and constant expungement requires DNA tests to be completed over and over again for the same offender who comes in and out of the system.

These arguments are likely to surface again and again as more states begin to collect DNA samples. There may not be a simple solution to the conflict between safety and privacy, efficient crime solving and personal freedom, but looking at the precedents set by other states and even abroad can help inform the arguments, helping us to reach an acceptable compromise.

For further reading:
DNA Resource
The DNA Initiative: Advancing Criminal Justice Through DNA Technology