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.

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.