Police Chief Raul Quezada said no one has been formally charged in the incident, which took place Tuesday afternoon as some teens walked home from school and has sparked protests.
Quezada and Mayor Tom Tait both said Thursday they were thankful no one was wounded when the officer fired a handgun into the ground.
"As a father and as a police chief, I too am disturbed by what I saw on the videos that were posted on the Internet," Quezada told reporters. He said he hopes a criminal investigation into the matter, which involved several teens and an off-duty Los Angeles police officer who lives in Anaheim, will be completed within two weeks.
The dispute occurred outside the officer's house over the issue of teens walking across his property, something Quezada said was an ongoing dispute. The officer got into an argument with a 13-year-old boy and wrestled with him while trying to detain him.
Officials said the first 911 calls from the scene came from either the officer or his father.
Parts of the encounter were recorded and posted on social media.
People who watched the video online became upset when they learned the officer was not arrested. About 200 to 300 people protested outside the officer's home Wednesday night.
A total of 23 people were arrested on misdemeanor charges as officers ordered protesters to disperse, according to the Anaheim police.
The mayor also said he was disturbed by what he saw on video.
"It should have never happened," Tait said. "Not in one of our neighborhoods, not near one of our schools."
He said the police department was conducting a full and impartial investigation.
Video footage of scuffle
One point of dispute is what the teen said to the officer.
Police said the 13-year-old boy allegedly threatened to shoot the officer, but the teen told CNN affiliate KTLA
he said he would sue the officer.
The eighth-grader said the conflict started when he and other students were walking home from school and a female student stepped on the officer's lawn. He said the officer cursed at the girl, and that's when he spoke up. The teenager said the officer then "came at me."
The youngster can be heard on video saying the man misheard him when he said he'd "sue him."
Recordings show a man wearing sunglasses and a teenager shouting and scuffling as a crowd of youths gather and watch.
"Let go of me," the teen yells as the adult holds onto his sweatshirt. "I'm only like freakin' 13!"
Then another young bystander intervenes, charging at the adult and knocking him over a row of bushes. Another teen races in and tries to punch the adult. Another boy approaches to the officer and reaches his hand toward a back pocket.
When the officer pulls out a gun and fires a shot, the crowd of about 20 teens quickly scatters.
Anaheim police arrested the 13-year-old boy for making criminal threats and battery. But after the videos popped up online he was released, the chief said.
Another boy, 15, was arrested, taken to a juvenile facility and released.
But Quezada didn't rule out charges in the future, against the officer or the teens.
He said the officer was not arrested Tuesday because there wasn't at that time "clear, compelling evidence of a crime."
Los Angeles Police Department Assistant Chief Michel Moore
said the unidentified officer is on administrative leave. Detectives conducting an investigation will look into whether the officer was justified to pull a firearm and whether deadly force was necessary. They also will look at the tactics the officer used.
Moore said he was prohibited by law from releasing any information about the officer, including how many years the officer had been on the force.
'Don't shoot the kids!'
Protesters have questioned why the officer didn't try to defuse the situation.
"At the end of the day there is no justification for him to pull a gun out, and he pulled it out around a crowd of children," one female protester told KTLA. "If he is a police officer, he should know better."
On Wednesday, protesters shouted: "Don't shoot the kids!" and "Whose streets? Our streets."
Some participants smashed windows of the officer's house, damaged cars and sprayed graffiti on a neighbor's house, according to KTLA.