PHILADELPHIA — The families of four young men killed and buried on a Pennsylvania farm are now suing the parents of the man who confessed in the killings.

Lawsuits filed Monday by families of three of the victims allege that Cosmo DiNardo's parents should have stopped their then 20-year-old son from having access to guns since he was barred from possessing firearms due to an involuntary commitment to a mental health facility.

The family of the fourth victim filed a similar lawsuit in December

A lawyer representing Antonio and Sandra DiNardo was out of the country and unavailable for comment.

Cosmo DiNardo's attorney has said he confessed to the July killings to be spared capital punishment. Prosecutors say they're on track to reach a deal with him. The attorney didn't immediately return a message seeking comment.