As police agencies have often been pushing for wider collection and cataloguing of DNA as investigatory helps, now some police officers are finding themselves at the other end of the DNA collection swab.

The New York Police Department (NYPD) is starting what some call a "DNA roundup" of its crime scene investigations detectives. The DNA cataloguing is to quickly spot DNA that may be accidental left by CSI people at a crime scene so the police aren't looking for that person based on DNA found at the crime scene. This is similar to the collection of elimination fingerprints from some crime scenes. (For example, the members of a household that was burglarised might be fingerprinted to help the police eliminate their prints from the prints of suspects. Law enforcement officers prints are also on file and, thus, any prints they accidentally left at the crime scene can be eliminated. [Note 1])

This DNA cataloguing was prompted by the complications in a recent murder investigation as police were seeking for a male suspect whose DNA was found at the crime scene. It turned it to belong to a CSI detective who washed his hands in a sink and left a small drop of his blood.

Despite the practical investigatory reasons for the DNA cataloguing, some police officers are objecting, citing privacy concerns. Rather ironic. But there are some legitimate concerns about the use of DNA for elimination purposes.

• DNA can tell things that fingerprints cannot. Fingerprint can tie evidence to an individual but not tell much about the individual himself. DNA can tell much about the person's physical traits, medical conditions, and such. One concern for CSI people could be adverse impact of some of the information for job promotions or insurance. [Note 2]
• A significant difference between fignerprints and DNA is the prospect of near match familial DNA searches. If one is fingerprinted, that record applies only to oneself. With DNA, that record can place one's blood relatives in a genetic lineup. This differnce can be unsettling to many people.
• Will the original agreement for the collection & cataloguing of the DNA change without notice & consent? Could the genetic information be "repurposed"?

The collection of the CSI peoples' DNA is still a good idea, but the issues such as the ones I mentioned above do need to be addressed.

J.D. Abolins

UPDATED 12 Nov 2008 to add more information and notes.

Notes:

1. Elimination prints and DNA do not mean that the person may never be considered a suspect. They eliminate people known to have legitimately been connected with the crime scene from initial searches for suspects based upon fingerprints and DNA themselves. Should other clues appear indicating that the "eliminated" person may have commited the crime, the person will become a suspect. This could happen, say, in a burglery case where other evidence is found that a household member may have taken the items reported as stolen and comitted insurance fraud.
2. The use of genetic infromation for employment and insurance purposes is addressed by some genetic privacy laws, such as the US federal Genetic Information Nondiscrimination Act (GINA) and various state laws. How well are the employment & insurance issues address is a matter I cannot cover in this post.
3. Slightly off-topic: As I was searching for more information about this DNA testing, I ran into a strange, novel approach to DNA testing: "DNA spit parties" Think of nucleic acids meet social networking.