Maryland Supreme Court ruling places limits on ballistics testimony

A Maryland Supreme Court ruling questions how reliable ballistics science is and how it can be used in criminal trials.

Attorneys for a convicted killer in Prince George’s County challenged whether crime scene analysts can definitively match bullets to a gun.

Maryland's highest court ruled the idea of a perfect match doesn't match up with the science. The court placed limits on what forensic experts can say in all cases involving guns moving forward.

Shell casings recovered at crime scenes are sent to a lab where technicians microscopically inspect them looking for evidence the casing can be linked to a weapon and, ultimately, a shooter.

“This specific type of testimony – this type of, this piece of ammunition was fired by this specific gun – this is absolutely routine,” University of Maryland College of Law professor Maneka Sinha said.

A former public defender, Sinha said she's seen too many cases where a forensic expert declared a specific casing came from a specific gun.

The Maryland Supreme Court ruling puts limits on that kind of testimony.

“They can still say that there is some pool of weapons that could have fired this and this gun that was recovered on the scene is within that pool,” Sinha said. “But they can't go further than that to say, ‘It was this gun,’ because the science    doesn't support that.”

Not only does the ruling change criminal cases in the future, but it could also impact many in the past.

“We have a case that was getting ready for sentencing, and they postponed sentencing this week so that they could pull the transcript and see exactly what the expert said,” Baltimore County State’s Attorney Scott Shellenberger said.

The issue is whether firearms experts have told jurors a bullet matched a gun, he said, which he admits is testimony jurors lean in to hear.

He’s telling his prosecutors to look at current and old cases.

“We will be pulling cases, checking transcripts and seeing if that testimony had been given on other cases,” Shellenberger said.

The technology has been used by police departments all over the country for years. It’s one of many pieces of evidence law enforcement rely on for prosecution.

Prince William County Police Chief Peter Newsham said he hasn’t reviewed the Maryland decision but still believes “as with most forensic evidence, [firearms testing] can serve as an investigative lead that needs to be corroborated.”

Shellenberger advises fellow prosecutors across the country pay attention to Maryland's ruling.

“It could happen in their state and, therefore, impacts the ones that they're trying this week and next week, and they may not know it for a couple of years,” he said.

“This is really a step in the right direction towards sort of uncovering those flaws and bringing them to the public's attention and making sure that convictions are based on reliable evidence,” Sinha said.

Another significant challenge to this science is about to be heard in D.C. next month. Under current law, a firearms examiner can’t testify a specific bullet came from a specific gun without offering the jury some limitations.

The commonwealth's attorney in Alexandria said in Virginia, experts can't testify a bullet matches a firearm, either, but can say it isn't impossible.