Families of Sandy Hook victims reached a $73 million settlement Tuesday in their lawsuit against Remington Arms, manufacturer of the AR-15 semi-automatic rifle used to kill 20 kids and six staff members in the 2012 massacre.

The nine families brought a class-action suit in 2014 against Remington Arms, which made the weapon used in the mass shooting, claiming the gun-maker sought to sell the military-grade weapon to the mentally ill.

Families of victims killed in the Sandy Hook Elementary School shooting have reached an agreement to settle a lawsuit against the company that made the murder weapon, for $73 million.

"These nine families have shared a single goal from the very beginning: to do whatever they could to help prevent the next Sandy Hook. It is hard to imagine an outcome that better accomplishes that goal," said Josh Koskoff, an attorney for the victims' families, in a statement on Tuesday.

Remington Arms agreed Tuesday to settle liability claims from the families of five adults and four children killed in the massacre at Sandy Hook Elementary School, according to a new court filing, marking the first time a gun manufacturer has been held liable for a mass shooting in the U.S.

Remington agreed to pay the families $73 million.