NYPD crime scene tape is seen at the site of a shooting at the corner of Marcus Garvey Boulevard and Pulaski Street in the Brooklyn borough of New York on July 9, 2012. Reuters

A Mount Vernon, Washington, police officer was in stable condition early Friday after being shot in the head by a gunman authorities feared was live streaming the crime on social media. The name of the officer, who has spent more than 30 years on the force, had not yet been released Friday morning. Neither were the identities of the three people arrested in connection with the shooting, according to the Sagit Valley Herald.

Authorities in Mount Vernon, a 30,000-person town about an hour's drive from Seattle, got a call at about 5:30 p.m. local time Thursday that a person had been shot on the street, NBC News reported. When they responded, the suspect turned on them, shooting the officer and then hiding inside a house nearby. The suspect and police then began a standoff that would last for more than six hours.

Washington State Sgt. Keith Leary told the Herald that the shooter had a violent criminal history and may have been using social media during the late-night standoff.

"If he is streaming this on Facebook, the best thing for him to do is give himself up and end this situation," Leary said at one point. "It’s not going to get any better."

Local residents evacuated while students at Skagit Valley College went on lockdown. Police thought the gunman had hostages, but they later amended their statement: Two people inside with the shooter were actually people of interest, the Seattle Times reported.

"I think, 'God, that sounds like a shot,' and then 10 seconds later I heard bang, bang — two more shots. And I looked around, and about 10 to 15 seconds later I heard a shot and then a rapid succession of shots like bang, bang, bang, bang, bang. Then I knew something was really wrong," neighbor Mark Fossati told KOMO News. "So it was pretty terrible."

Three people were taken into custody at about 12:45 a.m. local time after officers used tear gas to force them out of the house. The officer, meanwhile, was "hanging in there," Leary said during a news conference.