A Santa Rosa Junior College student walking to her car Tuesday evening was assaulted by a man who came up from behind, grabbed her buttocks and hit her in the face, police said.

The man then fled north into the campus but was chased down by the college's softball coach, who had heard the victim yelling, said SRJC Police Chief Matt McCaffrey.

Campus police arrested Jonathan Michael Hoppner, 20, on suspicion of misdemeanor sexual battery and battery on school grounds.

It happened at about 5 p.m. as the woman was near the Quinn Swim Center and the "C" parking lot. She said a man walked up behind her and grabbed her buttocks in a sexual manner, McCaffrey said. She spun around, shouted and shoved him, McCaffrey said.

"She had a good, aggressive response. Her yelling got people's attention," he said.

The man also hit her with an open palm, leaving red marks on one side of her face.

The man ran north into the campus and was confronted by coach Phil Wright, who had heard the woman calling for help as he was walking out of practice with his team.

"I heard this lady screaming," Wright said. "I didn't even think twice. I'm a dad, with two girls. I just dropped everything I had and ran out."

Wright said he sprinted alongside the suspect, repeatedly urging him to stop and wait for police.

"I was trying to calm him down and get him to stop," Wright said. "I was going to throw him to the ground. And the cops came around the corner."

McCaffrey said the victim and suspect didn't know each other.

Hoppner was cited and released on the misdemeanors. He also faces an immediate two-week expulsion from campus leading to an official review of the case by school officials and further possible school sanctions, said McCaffrey.

You can reach Staff Writer Randi Rossmann at 521-5412 or randi.rossmann@pressdemocrat.com.