Sonoma State University police investigating sexual assault during Green Music Center show

Sonoma State University police are investigating a sexual assault reported to have taken place Saturday during a performance at the Green Music Center on the Rohnert Park campus.

The 9 p.m. assault occurred outside at Weill Lawn where roughly 3,000 people were watching a performance by country star Chris Young at the center, according to university spokesman Nicolas Grizzle.

The female victim told campus police she did not know the man who assaulted her. Campus police described the suspect as a white man in his early 20s, about 6 feet tall with brown hair and “a thin, athletic, physical build.”

Police provided no other details about the incident and declined to answer questions about the nature of the assault, whether the woman was a student and if it occurred amid the crowd at the sold-out show, which started at 7:30 p.m.

Acting Chief David Dougherty referred questions to Grizzle, who said providing additional information “would potentially compromise the investigation and we can't comment further.”

Dougherty has been acting chief pending a university decision on the future of Chief Nathan Johnson, who's been on paid administrative leave since May for a brawl with his stepson at their Hayward-area home. The Alameda County District's Office filed no criminal charges against Johnson, but the university is conducting an internal review.

Sunday, police sent a campuswide email alert at 1:39 a.m. about the sexual assault.

On Wednesday, the university issued a second bulletin about an “ongoing investigation” that asked university staff and students to help identify a man in a grainy photograph. Police gave a similar description for the man in the photograph as a white male between 20 and 25 years old, about 6 feet tall and 190 pounds “with a muscular, athletic build, medium complexion and brown hair.”

He wore a gray shirt with a San Francisco Giants' “SF” logo, dark pants and a backward baseball cap.

The bulletin didn't say whether the unspecified “ongoing investigation” involving the photograph was related to the sexual assault. Grizzle declined to comment if the bulletins were related to the same case.

University president Judy Sakaki could not be reached for comment Thursday.

Anyone with information about the case can call the university's police department at 707-664-4444.

Staff Writer Julie Johnson can be reached at 707-521-5220 or julie.johnson@pressdemocrat.com.

Editor's note: This story has been revised to provide the correct date of the first campus-wide alert about the reported sexual assault. The alert went out at 1:39 a.m. Sunday.