Remington Arms. Co. LLC, the manufacturer of the AR-15 rifle used in the 2012 Sandy Hook Elementary School mass shooting, asked the U.S. Supreme Court to hear its appeal of a Connecticut Supreme Court ruling against it.

In its 277-page petition for a writ of certiorari, the gun-maker cited the federal Protection of Lawful Commerce in Arms Act that is meant to shield firearm makers from liability when their products are used in acts of violence. Its product was what gunman Adam Lanza used to kill 20 schoolchildren and six teachers at the school.