When Baltimore police arrested Thomas Royal during a traffic stop one winter morning in 2009, he was carrying a loaded revolver.

Not just any pistol, however. An antique Iver Johnson model handgun made in 1895. As a convicted felon, the pistol could have landed Royal in legal trouble. But federal law defines a firearm as a gun made in or after 1898.

Yet Royal wasn’t off the hook. Prosecutors got him on the charge of a felon in possession of ammunition—the five .32-caliber bullets found inside the antique gun. Royal was indicted in August 2009. He was later convicted and sentenced to 15 years in prison.

Royal’s lawyers, including Venable litigation partner James Fraser, now are trying to convince the U.S. Court of Appeals for the Fourth Circuit to erase the conviction. Royal’s attorneys argue prosecutors didn’t present evidence that the bullets were designed for use in a non-antique firearm. The appeals court will hear the case October 26.

“Under the plain language of the statute, bullets qualify as ‘ammunition’ only if they are designed to work in a non-antique firearm,” Fraser said in a court brief in the Fourth Circuit. (Fraser declined an interview request. Venable is representing Royal pro bono.)

A special agent with the federal Bureau of Alcohol, Tobacco, Firearms & Explosives testified at trial that the bullets traveled in interstate commerce, establishing a federal criminal offense. The agent said the bullets were made in either Connecticut, Arkansas or Illinois, according to court records.

Royal’s lawyers said the trial judge, Richard Bennett of U.S. District Court for the District of Maryland, refused to allow Royal to ask the agent whether the bullets were made before 1899. Bennett, according to court records, said “it is absolutely of no legal significance when the ammunition was manufactured.”

Fraser said in court papers that “of course, the fact that bullets were manufactured before 1899 would be evidence that the bullets were not designed for use in a firearm manufactured in or after 1899.”

“Given that the bullets in this case were found in an antique Iver Johnson revolver, and given the modern day interest in antique Iver Johnson revolvers…the government had the burden to prove that the bullets were designed for use in a non-antique firearm regardless of whether the bullets were manufactured in or after 1899,” Royal’s attorneys said in the appellate brief.

Bennett told jurors that the prosecution had the burden to prove that Royal knowingly possessed bullets—”ammunition as we commonly use the word,” the judge said. Royal’s attorneys contend Bennett should have instructed jurors that the government must prove the ammunition was designed for use in a non-antique firearm.

John Sippel Jr., an assistant U.S. attorney in Baltimore, will argue for the government in the Fourth Circuit. Sippel said in court papers that there’s ample evidence to uphold the conviction against Royal. He urged the appeals court to respect the jury’s guilty verdict. (Sippel declined to comment.)

“During trial, every witness discussed the ammunition that was recovered from the antique firearm found on Royal during his arrest and referred to its common meaning,” Sippel wrote in court papers. “At no time did the defense raise any affirmative defense as to the design of the ammunition.”

Fraser, who will argue for Royal at the appellate hearing this month, disputes the government’s argument that the burden was on the defense to prove that the bullets were not designed for a non-antique gun.

Royal got 15 years behind bars—a mandatory minimum term—because he was sentenced under the Armed Career Criminal Act. His lawyers are disputing whether one of his old crimes—an assault in Maryland state court—should have been included in determining his sentence under the career criminal umbrella.

Taking away the armed career criminal enhancement, Royal would face up to ten years on the ammunition offense.

Contact Mike Scarcella at mscarcella@alm.com.