Months after four young men were brutally murdered in Bucks County, Pennsylvania, the family of one of the men filed a wrongful death lawsuit. The family of Mark Sturgis filed a lawsuit Wednesday in the Philadelphia Court of Common Pleas against Sean Kratz, Cosmo DiNardo and DiNardo’s parents, WCAU-TV reported.

Sturgis, 22, Dean Finocchiaro, 19, Tom Meo, 21, and Kimi Patrick, 19, were found shot to death on a Bucks County farm belonging to the DiNardos in July. Cosmo DiNardo and his cousin, Sean Kratz, were charged in the deaths.

DiNardo and Kratz, both 20, pleaded not guilty to the charges leveled against them. The lawsuit filed Wednesday alleged that the gun used to kill the men belonged to DiNardo’s mother and that his parents did not adequately keep the gun away from him despite his history of mental illness, according to WPVI.

“With this lawsuit, the heartbroken parents of Mark Sturgis intend to hold accountable everyone responsible for the horrific death of their son, not just those who pulled the trigger,” said attorney Robert Ross, according to WCAU. “This includes those who negligently and carelessly permitted either of the accused to gain access to firearms and equipment used in these heinous crimes.”

DiNardo reportedly admitted to luring the men to the property before killing them and burying their bodies. The mens’ bodies were set on fired and buried in an oil drum, authorities said. The lawsuit filed Wednesday also claimed the DiNardos should not have allowed their son to access the farm equipment and the property itself.

Bucks County District Attorney Matt Weintraub reportedly filed paperwork asking to seek the death penalty in the case, according to WPVI.

An attorney for the DiNardo family refuted allegations that they were to blame for the deaths.

“There were not four families victimized by this matter, there were five families,” said lawyer George Bochetto, according to the Philadelphia Inquirer. “The DiNardo family has been absolutely crushed and devastated by what’s occurred. It’s regrettable that they would be subject to lawsuits when they themselves are grieving so heavily all over this.”

An attorney for Kratz also denounced the lawsuit in response.

“While any aggrieved party has the absolute right to file a civil lawsuit in this matter, it’s important to remember that there was absolutely no reason to file this suit before the conclusion of the criminal proceedings,” said criminal attorney Craig Penglase, according to the Inquirer.