In light of a U.S. Supreme Court decision declaring the law was too vague as to what constitutes a violent career criminal, a convicted murderer’s mandatory 15-year sentence on a gun charge will have to be re-examined, a federal appeals court ruled.

On Monday, the U.S. Court of Appeals for the Third Circuit held that Ronnie Peppers may have been wrongly sentenced to the mandatory minimum of 15 years in prison for being a felon in possession of a firearm under the Armed Career Criminal Act.

The appeals court held that the trial judge must determine whether the possible error of fashioning the sentence on the “residual clause” of the ACCA was detrimental to Peppers. The U.S. Supreme Court’s 2015 ruling in Johnson v. United States declared the clause to be ”unconstitutionally vague” about the definition of a violent offense.

“Because we have decided that Peppers’s sentence was imposed due to constitutional error given that he may have been sentenced pursuant to the now-unconstitutional residual clause of the ACCA, the district court must resolve whether that error was harmless,” Third Circuit Judge Kent A. Jordan wrote in the court’s opinion.

Peppers, who had prior convictions, was sentenced to life in prison in 2000 for the murder and a related charge—however, he successfully appealed the trial court’s denial of his request to represent himself, and the Third Circuit tossed the conviction, according to Jordan.

Rather than go through another trial, Peppers pleaded guilty to one count of being an armed career criminal in possession of a .22 caliber revolver and was sentenced to 15 years in prison.

The sentencing took into account his criminal history, which included robbery charges from 1979 when he was a juvenile; second, in 1984 for burglary; third, in 1984 for possession of instruments of a crime; fourth, in 1985 for escape; fifth, in 1985 for armed robbery and criminal conspiracy; and sixth, in 1993 for criminal conspiracy to commit unauthorized use of an access device, according to Jordan.

However, on appeal Peppers claimed his robbery convictions no longer qualified as violent crimes since Johnson invalidated the residual clause.

The issue was one of first impression for the circuit, Jordan said, as several other federal courts have been split on how to decide similar cases. But the court was definitive in Peppers’ case.

“Peppers’s prior robbery convictions do not qualify as predicate offenses under the ACCA because a conviction under Pennsylvania’s robbery statute does not categorically constitute a ‘violent felony,’” Jordan said.

Jordan likened vagaries in Pennsylvania law to the robbery statute at issue in the Johnson case.

“The Pennsylvania robbery statute criminalizes ‘physically tak[ing] or remov[ing] property from the person of another by force however slight,’” Jordan said. “Because that has been interpreted to include ‘any amount of force applied to a person while committing a theft[,]‘ including the mere ‘use of threatening words or gestures, and operates on the mind,’ and because ‘[t]he degree of actual force is immaterial, so long as it is sufficient to separate the victim from his property.’”

He continued, “Pennsylvania’s robbery statute suffers from the same issues the Supreme Court identified with Florida’s battery statute in Johnson 2010. Both laws proscribe the merest touching, which is insufficient conduct to meet the ‘physical force’ requirement under the ACCA’s elements clause.”

Frederick W. Ulrich of the Federal Public Defender’s Office of the Middle District of Pennsylvania represents Peppers and declined to comment.

A spokeswoman for the U.S. Attorney’s Office for the Middle District declined to comment as of press time.