The incident occurred about 10:10 a.m. at the intersection of Cypress Street and Vincent Avenue, according to the Los Angeles County Sheriff's Department.
A deputy from the San Dimas sheriff's station responded to the intersection on a report a woman was vandalizing vehicles and he saw her walking in the street with a large pipe wrench in her hand, sheriff's officials said. The woman walked up to the patrol unit and shattered its rear window with the wrench.
When she charged toward the deputy with the wrench, the deputy shot her, officials said. The woman was believed between 20 and 30 years old. The pipe wrench was recovered at the scene.
Paramedics rushed the woman to a hospital, where she was listed in critical but stable condition, officials said.
According to KeyNews Network, the deputy fired three shots at her. Witnesses told KeyNews Network that the woman had struck multiple vehicles in the area.
The sheriff's department urged anyone with information about the incident to call them at 323-890-5500 or Crime Stoppers at 800-222-8477