The news media is reporting that a suspect in a high-profile murder and arson case was identified through DNA found on a pizza crust at the crime scene. The suspect, Dylon Wint, was arrested last night at a Howard Johnson hotel in Washington D.C. He is suspected of killing four people inside a house after holding them hostage, and then setting the house on fire. The police found a pizza crust at the home (it’s still unclear on how the pizza crust was undamaged by the fire) and tested it for DNA since it was apparently delivered to the house while the people inside were being held hostage.

Can the police do this? Yes they can. But to get to that answer we have to look at it several ways:

Can the police collect DNA evidence from pizza crusts without a warrant? The answer is probably yes, at least in this case. Last year the Maryland Court of Appeals narrowly ruled that the police didn’t need a warrant to run a DNA swab on the armrests of the chair a suspect sat in during a police interview (the case may potentially be reviewed by the U.S. Supreme Court). Also, consider that the pizza crust was discarded by someone (probably the suspect), and courts have ruled pretty consistently that the police can test discarded things like garbage as long as they’re not in a location where the suspect has an expectation of privacy. Also, even if the police did need a warrant to test the pizza crust, they can argue that they still are entitled to use that information under the “inevitable discovery doctrine” – basically saying that they would have discovered the DNA anyway, with a warrant, so they didn’t really need to get one.

Can the DNA evidence be trusted? This remains to be seen. Crime labs across the country have been rife with problems. A story from earlier this year details how FBI forensic examiners gave flawed testimony over two decades in thousands of cases, including 32 where the defendant was sentenced to death. Sadly these problems are not new. Similar stories ran in 201420132011, and even 1997. That’s just a small sampling. But back to the case at hand. It wouldn’t surprise me if Wint’s attorneys challenge the forensic lab’s DNA analysis. But until they do, we won’t know if the evidence is truly accurate or not.

This case is certainly a tragic scenario. Let’s hope not only that justice is done, but that it’s done the right way.