The woman who shot three people at YouTube's headquarters produced many online videos and these are central to the motive authorities have identified - her anger with the policies of YouTube.
Nasim Aghdam who was in her late 30s, opened fire with a handgun and wounded three people at YouTube's headquarters, police said. She then killed herself.
She had posted videos under the online name Nasime Sabz, and a website in that name decried YouTube's policies, saying the company was trying to "suppress" content creators.
Many of the clips have been branded bizarre, such as one in which she removes a revealing purple dress to expose fake breasts with the message, "Don't Trust Your Eyes".
In others she exercises, promotes animal rights and explains the vegan diet, often in elaborate costumes or carrying a rabbit.
People who post on YouTube, the world's biggest online video website, can receive money from adverts that accompany their videos, but the company "de-monetises" some channels for reasons including inappropriate material or having fewer than 1,000 subscribers.
Nasim Aghdam also ran a Farsi-language public channel on the messaging app Telegram, which had 6,000 followers.
Telegram reportedly has some 40 million users in Iran. In one post she says: "Internet crackdown and filtering is increasing in the West."
Police found Nasim Aghdam sleeping in her car early on Tuesday in the city of Mountain View, about 25 miles (40km) from YouTube's headquarters.
They said she was calm and said nothing about being angry with YouTube or having any plans to harm others or herself.
"It was a very normal conversation. There was nothing in her behaviour that suggested anything unusual," said Mountain View Police Chief Max Bosel.
Later that day, Aghdam went to a gun range before walking through a car park into a courtyard at YouTube's campus south of San Francisco, where she opened fire.
Two women wounded in the shooting were released on Wednesday from a San Francisco hospital. The third victim, a 36-year-old man, was upgraded from a critical to a serious condition.
The suspect's father, Ismail Aghdam, told the Bay Area News Group he warned police the day before the attack that his daughter was upset with how YouTube handled her videos and might be planning to go to its offices.
Police in Mountain View said they spoke to him twice after contacting the family to report finding his daughter and that he never told them she could become violent or pose a threat to YouTube employees.
During her 20-minute interview with officers, Nasim Aghdam said she was having family problems and had left her home, police said.
Agents with the Bureau of Alcohol, Tobacco, Firearms and Explosives have searched two homes where Nasim Aghdam had lived - one in Menifee, which is southeast of Los Angeles, and another in 4S Ranch, north of San Diego.
Nasim Aghdam referenced a since-deactivated website, PeaceThunder, in a 2014 interview promoting veganism.
The state attorney general's website shows a charity group named PeaceThunder affiliated with Nasim Aghdan was dissolved at her request in 2011. She gave no reason but said she was its only member and the group had no assets.
John Rundell, who lives next door to the family in Menifee, said the parents, son and daughter moved from San Diego about five years ago, but he had not seen Nasim Aghdam in months.
The entire family was "very, very friendly", he said. "They were just perfect neighbours. If I had to pick neighbours, I'd have them all around."
The family turned away reporters at their home in Menifee. A woman named Leila who identified herself as an aunt said Nasim Aghdam was a "really good person" and had no history of mental illness.
The family later distributed a statement saying they were "in absolute shock and can't make sense of what has happened".
"Although no words can describe our deep pain for this tragedy, our family would like to express their utmost regret, sorrow for what has happened to innocent victims," it read.
It is not clear whether Nasim Aghdam encountered any security on her way to the YouTube building but the company said it will increase security at its headquarters and offices around the world.