On Tuesday, one of the men allegedly went to Harrison's brother's detail shop where another fight broke out. Shots were fired and two men were injured. Harrison showed up at the scene a short time later.
Police called him in for questioning. Harrison turned over a gun that produces unique bullet casings similar to ones found at the scene.
"He was interviewed," Vanore said Friday. "Why he was interviewed, that is all part of the investigation. No one is a suspect."
Investigators say Harrison is cooperating.
A source told WIP that ballistic tests showed the shots were fired from a custom-made Belgian weapon, and police determined Harrison owns that kind of gun.
Police went to a Philadelphia car wash owned by Harrison and questioned him about the gun, the station said. Harrison acknowledged owning such a weapon, but told officials it never left his suburban Philadelphia home, the radio station reported.
The source told the station a gun was discovered in a bucket at the car wash, and tests showed it had fired bullets that matched those at the scene.
Harrison, a Roman Catholic graduate, currently plays for the Indianapolis Colts.
After the first day of their rookie minicamp, Colts coach Tony Dungy said he knew little more than had been reported.
"My phone has been ringing, too, but I don't have any details," Dungy said. "I really don't have any more information than you do."
NFL spokesman Greg Aiello said the league is aware of the report and is "looking into it." Harrison's agent, Tom Condon, did not immediately return a call.
(Some information from The Associated Press.)