A woman was arrested on suspicion of driving under the influence in Rohnert Park on Saturday night after she hit a parked police car with a Toyota SUV, police said.
Police responded to reports of a large party at a residence in the 6300 block of San Rafael Court at 11:42 p.m.
Over 80 people were at the party, and when police arrived the home's resident began telling guests to leave and the crowd poured into the street.
The party guests were fighting, urinating in public, and police called for additional officers to help manage the large crowd.
Officers then heard a collision and saw that a Toyota SUV had collided with a police car.
The vehicles had minor scratches to the bumper, but police asked the driver to take a field sobriety test.
After the test, police arrested the driver, identified as Alexandra Hughes of Rohnert Park, and booked her into Sonoma County Jail on suspicion of driving under the influence.
Police said that while in jail Hughes took a breath test that indicated her blood alcohol content was over 0.20 percent.
The passenger in the car was the owner of the vehicle, who told police that she was too intoxicated to drive and gave her keys to Hughes, who had said she was "OK" to drive, police said.