The collision was first reported at 2:59 a.m. at the intersection of Hoen Avenue and Cypress Way.
Police say the driver of a Black Dodge Challenger hit a white Mazda SUV and a Black Prius.
A woman was sleeping in the Mazda, where police say she was living, along with her dog. They were both killed. No one was in the Prius.
The suspect has been identified as Angel Ivan Martinez, a 21-year-old resident of Santa Rosa.
"Investigators completed a DUI investigation and determined that Martinez was under the influence of alcohol at the time of the collision. He was treated for minor injuries at a local hospital and the booked at the Sonoma County Jail for vehicular manslaughter with a DUI and for two other counts for Felony DUI," said the Santa Rosa Police Department in a statement.
Police said the collision caused a power outage. PG&E's outage map shows more than 500 customers were impacted.