The videos show officer Richard Gonsalves firing four shots at Alfred Olango, an unarmed man, who was pointing the cylindrical vape pen at officers earlier this week. A woman can be heard screaming in the cell phone video as the shots are fired.
Officer Josh McDaniel, like Gonsalves an officer for 21 years, deployed his Taser.
A female employee of a fast-food restaurant recorded video on her cell phone, as did a surveillance camera above a drive-through window.
No decision has been made whether to file criminal charges against one or both officers.
"Any criminal conduct being pursued will be some time much later," San Diego County District Attorney Bonnie Dumanis told reporters.
On Tuesday afternoon, police responded to a 911 call reporting a man in his 30s was behaving "erratically" behind a restaurant.
Once they arrived, Olango kept his hands concealed in his pockets while pacing back and forth, police said.
The man "rapidly drew an object" and placed both hands on it "like you would be holding a firearm," police Chief Jeff Davis said.
One officer fired his gun at Olango, while a second officer discharged his Taser, police have said. Both are on three-day administrative leave.
The woman who called 911 claimed to be the man's sister and told the dispatcher he was mentally ill and unarmed, Davis said. Investigators have not been able to confirm whether the caller was Olango's sister, he said.
Olango's mother, Pamela Benge, said he was not mentally ill. He was mourning the loss of a friend, she said.
A psychiatric emergency response team was at another call but broke away and attempted to respond to the scene where police eventually faced off with Olango, Davis said Friday. The PERT team didn't arrive until after the shooting, the chief said.
Earlier this week, police released a video still showing the incident. Olango appears to be in stance as if ready to shoot, police said.
Officers were not wearing body cameras.
Olango's death set off demonstrations in the San Diego suburb. Protesters stopped cars and broke windows Thursday night, El Cajon police said. Protesters have called for the investigation into the shooting to be run by the US Department of Justice.
Businesses in downtown El Cajon were advised to close early Friday.
Olango came to the United States in 1991 as a refugee from Uganda.
Vape pens, or e-cigarettes, have been around for more than a decade but have boomed in popularity recently because of marketing to nicotine users looking for a safer alternative to smoking cigarettes. Also fueling the trend is the accessibility of oil concentrates. A vape pen creates an inhalable vapor with a small inner coil that slowly heats, creating a vapor that is inhaled.