The sergeant was involved in a minor collision with the man on Interstate Highway 280 around 12:10 a.m. Sunday, and both pulled off the highway and stopped near Jerrold Avenue and Bayshore Boulevard to exchange information, police said.
During that interaction, however, the man allegedly punched the sergeant and she then discharged her gun, police said. The bullet struck the pavement and some sort of fragment hit the suspect in the lower body, police Officer Albie Esparza said.
The man, identified as 37-year-old Joel Henriquez, refused medical attention, police said.
Henriquez, who was not armed, was arrested on suspicion of making criminal threats, battery on a police officer and making threats against an executive officer, Esparza said.
The sergeant, who has not been identified, has served with the force for at least 10 years and was placed on paid administrative leave as the shooting is investigated, Esparza said.