OAKLAND -- An Oakland Raiders fan was shot in the face by an Arizona Cardinals fan in a parking lot outside the teams' preseason football game in Glendale, Ariz., on Friday night, police said. It isn't known whether the shooting involved a fan dispute.

The 30-year-old Raiders fan was wearing silver face paint when he was shot, Glendale police said Tuesday, but it's unclear why the 57-year-old Cardinals fan, at the game with his wife, shot him.

"There has been absolutely no information obtained by investigators that would point to a specific conflict" between the two men over their team allegiances, Glendale police said in a statement. The shooting happened during the middle of the third quarter of the game.

The shooter had called 911 and told police the shooting was accidental. He has not been arrested, and officers continue to investigate, police said. A verbal skirmish preceded the shooting in the nearly empty parking lot, police said.

"What we can tell you is that there was not enough compelling evidence gathered on scene, through statements or physical evidence, to make the investigators comfortable with an arrest on the 57-year-old male," police said.

The Cardinals couple had been watching the game and left before it ended, police said. It was unclear whether the Raiders fan, who is in stable condition, had been in the stadium at any point.

Both the shooter and victim are Arizona residents, police said.

During the game, Glendale police arrested 14 people, ejected 11 and tallied 20 medical calls, with five people transported to hospitals.

In the police department's summary of its game activities, it said "a large number of fights occurred" inside University of Phoenix Stadium. The only outside incident noted was the shooting.

Contact Matthias Gafni at 925-952-5026. Follow him at Twitter.com/mgafni.