Police in Philadelphia, Pennsylvania are tracking a group of juveniles who, seemingly unprovoked, attacked a mentally-challenged man with sucker punches.
The slow-motion video showed the boys, two of them throwing punches at the man, as the other two watched and laughed.
Andrews said a co-worker alerted him to a video of the attack online - but doesn't know where it was originally posted.
In the 30-second video, which is doing rounds on the internet, a boy can be seen laughing while violently assaulting the man, identified as 38-year-old Mark Smith.
The boys are not being identified due to their ages. Police were made aware of the content and determined the video was recorded on Memorial Day at Chelten Avenue and Knox Street in Germantown.
Philadelphia police have arrested four boys, ranging in age from 12 to 15, in the beating of a disabled man that was caught on camera.
"Obviously, what is depicted in the video is very disturbing", police spokesman Sgt. Eric Gripp said.
Three of the boys were arrested at school Tuesday and released into the custody of their parents.
That happened two days before police say Fitler Academics Plus School principal Anthious Boone was hit with the brick while breaking up a fight between his students and some from nearby Mastery Charter schools.