A 26-year-old man — who lives in Delaware and was in town last week for the University of Colorado-West Virginia football game — now faces a felony assault charge after CU police said he punched an elderly man in the face while inside Folsom Field.

Michael Streicher was arrested about 8:20 p.m. Thursday on suspicion of third-degree assault and crimes against an at-risk adult because witnesses told police that he was fighting with someone next to him and inadvertently punched a man sitting below him.

CU police Cmdr. Brad Wiesley said witnesses reported that Streicher didn't know the 63-year-old victim from Denver and didn't mean to punch him in the face.

The victim, whose name wasn't released, was bleeding from the mouth and was treated at the stadium for his injuries.

Streicher was taken to the Boulder County Jail. The misdemeanor third-degree assault charge was upgraded to a felony because of the victim's age, Wiesley said.

"Because the man is over age 60, he's classified as an at-risk adult," Wiesley said.