Relatives whose loved ones were killed in the Sandy Hook Elementary School shooting are making an impassioned plea to the U.S. Supreme Court to uphold state and local bans on certain semiautomatic rifles, citing the high body counts and devastating injuries the weapons can inflict.

The parents of five of the 20 first-graders killed in the 2012 Connecticut shooting and relatives of one of six educators who died filed a “friend of the court” brief on Wednesday, weighing in on two cases challenging bans in Connecticut and the Chicago area. Justices are scheduled to hear oral arguments in both cases on Dec. 2.

“The assault on Sandy Hook Elementary School , carried out by an untrained, 112-pound youth armed with an AR-15-style rifle, is graphic proof of the unusual and extreme lethality of that firearm and the harm it is capable of inflicting on American communities,” the relatives' filing says.…