The San Mateo County district attorney explains they were airsoft replica guns and that the attorney general's office has now taken over the investigation.
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Just before 7:30 a.m., the San Francisco Police Department responded to San Francisco International Airport after receiving multiple calls for a suspicious man.
"He appeared to be armed with a handgun," said SFPD spokesperson Officer Grace Gatpandan.
Officer Gatpandan would not specify the de-escalation tactics officers used but did say the interaction was approximately 45 minutes.
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"It was enough time to get resources to this location to help de-escalate the situation," said Gatpandan.
Officers shot and killed the man. Police have not said how many officers fired their weapons or how many shots were fired.
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The San Mateo County District Attorney's Office was initially investigating until this afternoon when the attorney general's office was called in to take over.
San Mateo County District Attorney Steve Wagstaffe says that's because the guns the suspect had were not real firearms.
"What they determined was those firearms were airsoft guns," said Wagstaffe.
In other words, Wagstaffe says, replicas.
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"Whenever there is a fatal shooting by a law enforcement officer of what is defined as an unarmed person, the district attorney's office does not conduct the investigation. That will be conducted under the law by the attorney general's office and that is what happened here," said Wagstaffe.
Wagstaffe says the suspect also had a knife. He saw pictures of the two guns.
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"They absolutely looked real to me," said Wagstaffe.
"If I were standing and a man across from me was holding those I would assume he had a firearm that could be used to harm me," he continued.
Wagstaffe confirmed airsoft weapons sometimes have an orange tip distinguishing them from real firearms. He says in this case they did not and it's possible that tip was cut off.
"Melanie, we've seen that happen many times," said Wagstaffe.
An airport customer service agent described escaping to a designated safe area.
"We just got all the passengers we were in the middle of checking in flights and it was pretty scary," said Claudia Avalos.
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While passengers were thankful.
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"Sorry he lost his life but better than innocent people," said Cheryl Comfort-Brown.
San Francisco police say a bystander was injured and treated on the scene. He was taken to a local hospital with non-life-threatening injuries.
There are many cameras around SFO. Investigators have not said how the man got inside the terminal and whether or not he took BART. Police said there was no indication terrorism was involved.
SFPD says they will hold a town hall about the shooting within 10 days.
Wagstaffe would not comment on the AG's investigation specifically but in general, said in these types of cases, the question becomes was it reasonable for officers to believe the suspect had a real gun and that their lives were in danger.
"We can not expect our law enforcement to try and engage in the concept of well is it real or not real, by then it may be too late," said Wagstaffe.
California Attorney General Rob Bonta announced in a press release on Thursday that the California Department of Justice is investigating and will independently review this case. Under Assembly Bill 1506 (AB 1506), state prosecutors are required to investigate incidents involving officers that resulted in the death of an unarmed person.
EDITOR'S NOTE: Earlier authorities reported the shooting had occurred near the SFO BART station, however, it was later determined it actually occurred inside the terminal.