Idaho police officers opened fire from behind a chain-link fence just seconds after exiting their patrol cars and critically wounded a teenage boy — described by his family as nonverbal, autistic and intellectually disabled — as he stepped toward them with a knife, video from a witness shows.

Seventeen-year-old Victor Perez, who also has cerebral palsy, remained hospitalized in critical condition Tuesday after having nine bullets removed from his body and having his leg amputated, Ana Vazquez, his aunt, told The Associated Press. Doctors were planning tests on his brain activity.

“We don’t know if he’s going to wake up,” she said.

The shooting Saturday in Pocatello outraged the boy’s family and neighbors as well as viewers online who questioned why the officers opened fire within about 12 seconds of exiting their patrol cars while making no apparent effort to de-escalate the situation or use less lethal weapons. Dozens of protesters gathered outside the police department Sunday, eastidahonews.com reported.

There is no indication the police were aware of the boy’s conditions.

“The police barely spoke to anyone,” Vazquez said. “They just said get back and they just, they shot to kill.”

In a video statement posted to the Pocatello Police Department’s Facebook page on Monday, Chief Roger Schei said he wanted to “provide clarity, share the information we can at this stage and address some misconceptions that have emerged.”

“We understand the concern and emotion surrounding the officer-involved shooting that occurred,” he said, adding, “We are also aware of the video circulating online, which shows only one angle. The full picture requires careful review of all facts and evidence.”

Brad Andres, who took the video, has an auto shop nearby and told the AP he noticed a disturbance when he stepped outside to take a phone call around 5:20 Saturday. His 19-year-old son, Bridger, called 911 and reported it as a domestic dispute in a backyard.

The 911 caller said an apparently intoxicated man — the teen — was wielding a kitchen knife and periodically chasing a man and woman in the yard, according to audio of the 911 call released by the Pocatello Police Department.