Federal prosecutors say Jonathan Butler stood under a tree and fired at the chopper in July 2008, despite the nearby crowd in the courtyard of a North Philadelphia housing project.
Police overhead were trying to locate suspects who were illegally riding all-terrain vehicles. The helicopter was not hit.
Butler's attorney, David S. Bahuriak, says no one saw his client point the gun at the chopper. But police recovered a still-warm gun from Butler's waistband.
On Wednesday, a jury convicted Butler, of Harrisburg, of charges including interfering with a person operating an aircraft. Sentencing is set for Nov. 2.
