Explainer

Do Statutes of Limitations Apply to DNA Cases?

Last week, the New York Times reported that Milwaukee, Wis., prosecutors had filed rape and kidnapping charges against a “John Doe” defendant identifiable only by the DNA code of his semen. (DNA, like fingerprints, is unique to each individual.) The prosecutors took this step because the statute of limitations for the crime was about to expire and they had no better way of identifying their suspect. In cases where DNA evidence is located, will statutes of limitations become irrelevant?

Statute of limitations laws require plaintiffs to take legal action within a specified time in order for their claim to be valid. (Murder is the one crime exempted from statutes of limitations.) The purpose is to guarantee defendants’ Sixth Amendment right to a speedy trial and to ensure that they will not have to defend themselves against stale evidence. (It would be difficult, for example, to find witnesses to corroborate an alibi many years after the fact.)

In general, a warrant must be signed–or, in a civil case, a complaint filed–before the statute of limitations expires. In Wisconsin, where the statute of limitations in rape cases is six years, a warrant requires a name, an alias, or a physical description of the suspect that would allow him to be arrested with reasonable certainty. This ensures that prosecutors are charging a specific suspect. It also prevents them from bringing charges in secret, which would violate Fifth Amendment due process rights.

Some defense attorneys say that allowing prosecutors to charge suspects by their DNA would effectively suspend the statute of limitations because DNA is recovered in a very large percentage of criminal cases. And if a suspect can be charged by his DNA, why not charge other John Does by their fingerprints, which are ubiquitous at crime scenes, too?

The Milwaukee case does not necessarily imply such an expansion of prosecutorial discretion. In most crimes where DNA comes into play, its presence does not definitively prove guilt. A trace of DNA on a murder weapon, for example, only demonstrates that the suspect touched it–not that he actually committed the crime. But the Milwaukee suspect’s DNA was extracted from semen swabbed from the victims’ genitals on the nights of the attacks. Arguably, few fingerprints (or other identifiers) would be sufficiently persuasive for a warrant to be issued on their basis alone. The Milwaukee case would likely set a precedent only for the small set of cases where DNA is overwhelming proof of guilt. (Defense lawyer Barry Scheck took this position on CNN’s Burden of Proof. Click here to read a transcript of the discussion.)

It could also be argued that charging an individual by his DNA amounted to charging him in secret because few people would recognize their own genetic code even if they read it in a newspaper. In any event, the statute of limitations questions surrounding the Milwaukee case will be moot until prosecutors apprehend a suspect, match his DNA to John Doe’s, charge him with the crime, and his lawyers protest the prosecutors’ strategy.

Next question?