Law Blog

Appeals Court Upholds Mandatory DNA Testing for Arrestees

One of the big controversies in criminal justice system is how, and whether, we should catalog the DNA of criminals.

Everyone is well aware of the fact that a comprehensive DNA database would be a major asset in most criminal investigations, making it easier to identify suspects, and rule out innocent people early in the investigative process.

DNA evidence has, without question, already revolutionized criminal investigations. A single strand of hair or drop of blood can be enough to catch a violent criminal who might have otherwise gone free. Of course, DNA evidence isn’t useful unless there is a suspect to compare it to. A DNA database, which would take and record DNA samples from everyone who goes through the criminal justice system, would make it far more likely that a sample collected at a crime scene can be traced back to the person it came from.

A federal law allows federal law enforcement officers to collect DNA samples of all federal arrestees (people arrested by federal agencies such as the FBI, DEA, Secret Service, etc.). This law is somewhat unique, because most state laws allowing the collection of DNA only authorize it for people who are actually convicted of crimes. A law allowing DNA collection from anyone who’s arrested (whether or not they’re ultimately convicted) would, obviously, be much more far-reaching. Such a law has just been upheld by the 3rd Circuit Court of Appeals. Most other federal courts have only gone as far as to allow DNA collection after conviction. This means that the issue is almost certain to head to the Supreme Court.

Some privacy advocates claim that this puts us on an inevitable slide to something like mandatory DNA testing at birth, so that every single American will eventually be in a DNA database. Obviously, this is a serious concern. However, I think that the privacy concerns involved in creating a DNA database are a little overblown.

After all, DNA is really just a way of identifying a person, like fingerprints. It just happens to be far, far more accurate than fingerprints, and it’s much more difficult to eliminate detectable levels of DNA from a crime scene (a single hair, a speck of blood, or flake of dead skin can be enough to identify a person) than it is to eliminate fingerprints. Obviously, this makes DNA a very good way to identify a person. And, it’s standard procedure to take a person’s fingerprints when they’re arrested.

And, like DNA, fingerprints are used by the police solely to confirm a person’s identity.

Privacy advocates do raise an important point, however: a person’s DNA can reveal far more about that person than just their identity. It can also reveal if the person has any genetic diseases, or genetic predisposition to diseases, such as cancer, heart disease, and stroke, among many others. This is a major privacy concern, of course.

However, it should be noted that DNA tests that are used to ascertain identity only look at so-called “junk” DNA – long sections of the gene sequence that serve no apparent purpose, and cannot reveal much information about a person, other than their identity. Of course, if you take a DNA sample (using blood, a cheek swab, etc.), you have access to their entire genome, so sensitive information can still be accessed.

Obviously, there would need to be strong safeguards in place to prevent this type of information from being exploited. Exactly how the safeguards would work isn’t clear. I have no idea if this is possible, but perhaps only the gene sequence (which can be easily represented as a series of letters) necessary to identify a person could be digitized, and the rest discarded. Afterwards, the biological sample that was used to collect this information could be destroyed.

I’m sure that some people who are far smarter than I am could figure out other methods for protecting a person’s genetic privacy.

However the Supreme Court rules, this story goes to show, if we didn’t already know, that the 20th Century is long over, and the 21st is well underway. Unfortunately, in many respects, our legal system is still mired in the 20th Century. While it has caught up in many ways, the fact that it is still wrestling with issues such as this shows that it still has a lot of catching up to do. Not that it should dispose of these issues hastily, of course.