The man who killed six people and injured seven more in a series of drive-by shootings in Santa Barbara on Friday posted a YouTube video threatening to go on a killing spree just hours before the attack.

The shootings happened in the area of Isla Vista, near the campus of the University of California-Santa Barbara, where Elliot Rodger was a student, with the killings described as “premeditated mass murder” by Santa Barbara County Sheriff Bill Brown.

Police were alerted to reports of black BMW was seen speeding around the area and shooting at pedestrians at around 21:30 on Friday (04:30 GMT on Saturday). The responding officers exchanged gunfire with the gunman, who eventually crashed his car and was found dead with a bullet wound to the head. It is currently unclear whether he was shot by police officers or killed himself before he could be arrested.

A semi-automatic handgun was recovered from the vehicle.

Authorities have not named the gunman, but but Peter Rodger’s lawyer, Alan Shifman, said on Saturday that the “family believes the child [Elliot Rodger] was the perpetrator”.

Before the shootings, Rodger had posted a number of videos to YouTube where he complained about feelings of rejection and his failures in finding a girlfriend, and threatened to go on a killing spree around a sorority house at UC Santa Barbara, saying:

“Tomorrow is a day of retribution”

A number of those killed were shot at a sorority.