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,

In 20 seconds, the four officers got out of their vehicles, drew their guns, lined up behind the yard’s chain-link fence between them and the teen, and fired their weapons.

Video shows the moment Pocatello police open fire on a teenage boy holding a knife who is mentally and physically disabled. The Pocatello police chief says the shooting is under investigation.