Nikolas Cruz is the man suspected of killing 17 people at Parkland, Florida's Marjory Stoneman Douglas High School in February.
Newser reports he allegedly attacked a guard in jail Tuesday night.
WSVN reports it started when Cruz was asked by a sergeant to stop dragging his sandals while walking around a dayroom.
Allegedly, Cruz then flipped off the guard, "rushed him and attacked him in the face," getting on top of him and punching him multiple times.
NBC reports Cruz was been charged with two counts of aggravated assault on an officer.
He was also charged with one count of use of an "electric or chemical weapon against a law enforcement officer," NBC News reports.