A Maryland appeals court reversed the conviction of Gary Smith, a former U.S. Army Ranger charged in 2006 with fatally shooting his roommate inside their Montgomery County apartment — setting the stage for a third trial in the case.

In the latest iteration, filed Thursday, the Maryland Court of Special Appeals ruled that Montgomery Circuit Judge Eric Johnson erred by not asking prospective jurors a question that defense lawyers wanted him to ask: “Is there any member of the panel who would be less likely to believe a witness simply because they were called by the defense?”

Omitting the question was grounds for reversal, according to the appeals court, which also addressed other possible trial errors. Among them, prosecutors were permitted to admit evidence relating to Smith owning eight firearms and keeping ammunition in his apartment, issues that the appeals court termed “highly prejudicial” and, at best, only of limited relevance.

“We’re ecstatic to get another opportunity to prove Gary’s innocence,” said one of Smith’s attorneys, Andy Jezic.

Montgomery Deputy State’s Attorney John Maloney — who has twice tried Smith in the fatal shooting of Michael McQueen, another former Ranger — said that prosecutors will ask the state’s higher appellant court to reverse Thursday’s ruling.

If the ruling stands, the case would be sent back to Montgomery for a possible third trial.

“We’re confident that if he has to be tried again, he will again be found responsible for killing Michael McQueen,” Maloney said.

The case has significant trial-appeals-reversal history.

In 2008, Smith was convicted of depraved-heart, second-degree murder and use of a handgun in the commission of a felony. During the trial, jurors watched a video recording of Smith speaking with detectives, during which Smith changed the details of his story but asserted that McQueen shot himself. Prosecutors said that Smith shot McQueen at close range.

But that conviction was later reversed on a witness issue, setting the stage for a trial that began in 2012. This jury convicted Smith of a lesser charge — involuntary manslaughter — as well as use of a handgun in the commission of a felony. It was that trial that was the subject of the latest appeal.

Amid the appeals, Smith’s attorneys persuaded a different panel of judges to reduce Smith’s sentence — from the second trial — from 28 years to 15 years. Jezic said Smith will be eligible for a second parole hearing in two years.

A new trial in the case could start within eight months, Jezic said.