DENVER -- Boulder police have arrested a transient they said tried to set another transient on fire in front of a popular book store near the University of Colorado campus.

Police said they arrested Robert Sparks Byron, 62, on charges of first-degree assault, said police spokeswoman Sarah Huntley.

Police said Byron used an aerosol can and either a lighter or match to set the victim on fire Tuesday afternoon, Huntley said.

The victim was identified as Robert Colehour, 44. Coulehour was taken to the Boulder Community Hospital with second-degree burns to his right ear and neck as well as less serious burns on his arm and scalp, Huntley said.

Colehour is also a transient, she said.

Police are still investigating what led to the assault.

The assault took place in front of the Colorado Bookstore at the intersection of 13th Street and Broadway on the University Hill.

The manager at Jones General Store, across the street from the bookstore, told the Daily Camera both the victim and the suspect are regulars to the Hill area and both can be unpleasant.

Moschetti said he was across the street outside his store when he saw the two men arguing before the incident.

He said the victim walked away after the assault and the suspect stayed behind. "He was sitting there like you could set someone on fire, an there would be no consequences," Moschetti told the Camera.