Cosmo DiNardo allegedly joined in social media chatter about Dean Finocchiaro before the teen was found dead.
Photos showing accused Pennsylvania killer Cosmo DiNardo brandishing a gun have surfaced following his reported confession.
Read: Second Person of Interest Arrested in Case of Slain Pennsylvania Men: Report
DiNardo shared images of himself with a maniacal expression and wielding a gun as he participated in a private Snapchat group with local youths. In the chain of messages, they speculated about the disappearance of 18-year-old Dean Finocchiaro.
"Cosmo isn’t your buddy Dean missing aren’t you worried?” one person in the group said.
DiNardo replied: "I know the kid but yeah I feel bad for his parents. He's a pill-popping junky who had 2 DUIs and got popped for stolen bikes and guns. He prob just jumped parole or probation."
DiNardo has since admitted to killing Finocchiaro and three other Pennsylvania men, according to his attorney.
The 20-year-old and his cousin, Sean Kratz, also 20, were charged and arraigned for murder on Friday. No bail was set for either.
DiNardo has been charged with the murder of Finocchiaro, 19-year-old Jimi Patrick, 21-year-old Tom Meo and 22-year-old Mark Sturgis. Kratz was charged with the murders of Meo, Finocchiaro and Sturgis.
Kratz allegedly used heavy construction equipment to dig a 12-foot grave in which the victims were buried. The grave site is located on a $5 million farm owned by DiNardo's parents.
Read: Person of Interest Arrested in Case of 4 Missing Pennsylvania Men
"There was an attempt to burn the bodies, to deface them, to obliterate them, but I don’t believe that was successful," Bucks County DA Matthew Weintraub said in a press conference Friday. "We were able to secure the two weapons that we allege were used in these four murders."
Weintraub confirmed that the remains of all four men have been found.
Kratz was reportedly arrested after his cousin told cops he'd been involved.
One source reportedly says the murders happened because DiNardo felt "cheated" after several drug deals.
Watch: Police Searching for 4 Young Men Who Went Missing Within Days of Each Other
