Is DNA more like GPS or like fingerprints?

On February 2nd, David Savage reported on an upcoming Supreme Court oral argument regarding the 4th Amendment search and seizure clause.[1]  The case deals with the standard procedure, practiced in 28 states and by the federal government, to take DNA samples of most individuals arrested for serious crimes.  The case before the Court is Maryland v. King.[2] King was arrested for rape, among other charges, in Maryland in 2009.  His DNA profile also matched a case from 2003 involving the rape of two pre-teens.  King was convicted of all three crimes.


King’s argument deals with probable cause.  He was arrested for one crime, but there was no evidence or suspicion that connected him to the earlier crime.  Therefore, the search and seizure of his DNA for the purposes of comparison to all other DNA is unconstitutional.  Commentary on the case links the question presented to the GPS case from last term, US v. Jones.  There the Court ruled that the placement of a GPS device on a suspect’s car was a search that violated the 4th amendment.  Now in Jones, Scalia says, “It is important to be clear about what occurred in this case: The Government physically occupied private property for the purpose of obtaining information.”[3]


It seems pretty clear that if a GPS device placed on a car requires probable cause and a valid warrant due to the infringement of privacy and the amount of details of life that can be gathered, certainly the taking of DNA evidence falls squarely within that precedent.  DNA provides more information than any other physical evidence from a person.  It provides medical information, it provides familial information, and it is unique to an individual.  Savage quotes a DNA law expert as saying, “If you are arrested for a drug crime, that doesn’t mean the police can walk into your house looking for evidence of other crimes.”[4]  Again, if Jones is the controlling precedent, then the privacy interests will clearly outweigh the interests of the state.


Yet, there are several precedents that would support the practice of taking DNA samples after arrest.  First, providing DNA evidence is no more invasive than fingerprinting and the Court noted in Hayes v. Florida[5] that “None of the foregoing implies that a brief detention in the field for the purpose of fingerprinting, where there is only reasonable suspicion not amounting to probable case, is necessarily impermissible under the Fourth Amendment.”  And, fingerprint evidence can also be compared to outstanding cases and provide a match for the purposes of connecting one crime to another without suspicion.  We do not consider such comparisons of fingerprints to databases to be searches that run afoul of the constitution.


While DNA evidence does contain a great deal of information, the purpose for the collection and the use is the same as fingerprinting.  The scope of the search and the invasiveness of the seizure are quite similar.  In 1988, the Court also allowed the seizure and subsequent search of the curbside trash left by narcotics traffickers.  Despite Brennan’s protest from the dissent that our trash contains a great deal of personal information about our habits, our medical condition, and “intimate details of Greenwood’s private life…” , the Court ruled in CA v. Greenwood that you have no privacy expectation over your trash, once placed outside your house and curtilage for pickup.[6]


Pundits suggests that cases such as Jones and King will be harder for the justices as they deal with modern technology.  However, the justices can also eschew those arguments by making the analogy of DNA to fingerprints.  For political scientists, it will be informative to see which stimuli (privacy versus law & order) are hit during oral argument.  The framing of the case will likely determine the outcome.

[4] This, however, is not true.  The police can do some searching of home or the area around an arrestee under the many exceptions to the warrants rule.  Any evidence in plain view—evidence of other crimes—is fair game.  They can conduct a protective sweep, Maryland v. Buie, and again evidence in plain view is then admissible.


Leave a comment

Filed under Investigations and Evidence, The Right to Privacy

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s