A law enforcement official has identified the suspect in a shooting at YouTube headquarters as Nasim Aghdam of Southern California.
The official who was briefed on the investigation spoke to The Associated Press on the condition of anonymity because they were not authorized to discuss it.
NBC Bay Area reported that Aghdam had ranted online that YouTube had "discriminated and filtered" her videos, cutting her viewership.
San Bruno Police Chief Ed Barberini says a woman opened fire with a handgun in an outdoor courtyard Tuesday, then killed herself. Police provided no motive or other details about her.
Hospital officials have said a man is in critical condition and two women are in serious and fair condition.