Napa police identified a bicyclist Tuesday who was injured when he was hit by a car on Monday morning as Kenneth Prosser.

Prosser, 76, of Napa, suffered head and other injuries when he was struck by a Lexus traveling south on Soscol Avenue around 8 a.m., Sgt. Paul Paniagua said.

Prosser, who was wearing a helmet at the time of the collision, was taken to Queen of the Valley Medical Center in Napa, where he was in serious condition Tuesday afternoon.

When officers arrived to investigate the crash, they saw that the driver of the Lexus, Jenna Rubio, 23, of Napa, showed signs of impairment, police said.

Investigators said they believed that Rubio was under the influence of marijuana and prescription medications, police said.

Rubio was arrested after the accident on suspicion of felony DUI.

California Highway Patrol Officer Jake Ramos said Rubio had previously been arrested for misdemeanor DUI involving drugs while driving on the Silverado Trail south of Oak Knoll Road in unincorporated Napa County around 10 p.m. last Wednesday.