Ismail Aghdam told Mercury News that his daughter had "gone missing for a few days" and said he had "called law enforcement in the San Diego area because he was concerned about her recent ire at YouTube".
When police contacted Ismail Aghdam early Tuesday morning, they reassured him they had found his daughter "safe in her car" in Mountain View.
They told him everything was "under control", he said.
But when the family realised that was close to the YouTube headquarters, Aghdam said they told police about her recent complaints of how the company was "ruining her life", CBS reports.
"They claim police told them they would be keeping an eye on her."
Aghdam, wearing glasses and a scarf, reportedly let off as many as 40 shots with a 9mm handgun, wounding a man and two women sitting at an outdoor seating area, before she killed herself at approximately 1pm local time.
Law enforcement officials respond to the shooting at the YouTube offices. Photo / AP
The shooting spree caused panic and chaos at the company as terrified staff ran for their lives.
Her father's account follows news the boyfriend of the suspected shooter at YouTube headquarters was one of three people shot in what police described as a domestic dispute.
It comes after authorities question the motive for the woman who had previously ranted about the company and accused it of discriminating against her.
Police are attempting to understand the motive behind the attack but Nasim Aghdam's public outcry over recent changes to YouTube that affected how much money she earned was being investigated.
Shooter's YouTube rants
The 39-year-old posted a video on YouTube in January 2017 where she said YouTube "discriminated and filtered" her content.
She accused the company of being the culprit behind her channel getting less views, and in a fiery spray the following month, said there was "not equal growth opportunity on YouTube".
According to ABC7, she wrote on her website: "Be aware! Dictatorship exists in all countries but with different tactics!"
Police are attempting to understand the motive behind the attack but Nasim Aghdam's public outcry over recent changes to YouTube is being investigated.
She went on to say the "mental and physical health" of people was at risk by companies who were "destroying family values, promoting materialism and sexual degeneration in the name of freedom and turning people into programmed robots!".
She then quoted Hitler: "Make the lie big, make it simple, keep saying it and eventually they will believe it."
The rest of her message was dominated by her scathing words for YouTube.
"There is no free speech in the real world and you will be suppressed for telling the truth that is not supported by the system. Videos of targeted users are filtered and merely relegated so that people can hardly see their videos."
Her YouTube videos have been removed, as have her Facebook and Instagram accounts.
Aghdam turned the gun on herself after she shot three people at the San Bruno, California, offices.
Witnesses said Aghdam did not have an identification badge on her — as staff are supposed to — but was carrying a purse.
YouTube product builder Todd Sherman tweeted that he saw "blood drips" as he fled the building following the gunfire.
"I looked down and saw blood drips on the floor and stairs. Peaked [sic] around for threats and then we headed downstairs and out the front," he tweeted.
Sherman said he thought the sound of people running was an "earthquake" at first but soon realised a shooter had stormed the building.
San Bruno Police Chief Ed Barberini said Aghdam's body was found inside the building.
"We have one subject who is deceased inside the building with a self-inflicted wound," Barberini said.
"At this time, we believe it to be the shooter."
Barberini said four people had been taken to hospital, including three with gunshot wounds.
A woman opened fire at the YouTube headquarters in San Bruno, California today. Photo / AP
Asked about the shooter's motive he said: "We know very, very little right now, and we probably won't know more until tomorrow morning."
A hospital spokesman said a 36-year-old man was in critical condition, a 32-year-old woman was in serious condition and a 27-year-old woman was in a fair condition.
In his first public comments on the shooting, President Donald Trump tweeted: "Our thoughts and prayers are with everybody involved. Thank you to our phenomenal Law Enforcement Officers and First Responders that are currently on the scene."
Chris Dale, head of communications for YouTube said it felt like "the entire community of YouTube, and all of the employees, were victims of this crime".
