Dinardo and Kratz are cousins, the criminal complaint states.
DiNardo's lawyer announced that his client had admitted to the killings and was co-operating with investigators.
A person with first-hand knowledge of DiNardo's confession said he killed the men after he felt cheated or threatened during three drug transactions and then burned their bodies at his family's farm.
Cosmo Dinardo's attorney, Paul Lang, said Dinardo made the confession to Bucks County District Attorney Matthew Weintraub and told investigators where the bodies were buried in exchange for avoiding the death penalty, reported Reuters.
"There was an attempt to burn the bodies, to deface them, to obliterate them, but I don't believe that that was successful", Weintraub said.
"I'm sorry", a shackled DiNardo said as he left the courthouse, according to the AP. His family owns the suburban Philadelphia property where human remains were found Wednesday in a 12-foot-deep common grave. By, Wednesday DiNardo was arrested again for one count each of theft and receiving stolen property. A second suspect was also arrested and charged in three of the deaths.
Weintraub has said there were indications that some or all of the men knew one another and investigators were working to confirm the extent of any connections.
In a news conference Wednesday, District Attorney Matt Weintraub said he couldn't confirm the grand jury.
Positing that DiNardo who was Facebook friends with one of the victims and had a previous outstanding firearms warrant against him, authorities brought DiNardo in on Monday as they sought to "explore" possible involvement.
DiNardo was arrested earlier this week on charges stemming from the investigation.
Training goes a long way, but dogs are genetically better than other animals at sniffing out specific scents, said Dave Pappalardo, owner of K9 Unlimited, which trains dogs for law enforcement and civilians.
The three of them drove back to Dinardo's large property.
Finocchiaro's remains were found Thursday after a search intensified on the vast property owned by DiNardo's family.
The property belongs to Antonio and Sandra DiNardo.
"This painstaking process will go on, we're not done yet", Weintraub told reporters.
According to an affidavit of probable cause obtained by Digital First Media, DiNardo, who is diagnosed with schizophrenia, tried to sell Meo's vehicle, a 1996 Nissan Maxima, to a friend who lives in Bensalem for $500 on Saturday night.
The source said DiNardo was known to sell quarter-pounds of pot for several thousand dollars a pop, along with handguns. Dinardo allegedly used the backhoe to lift their bodies up and put them in the metal tank with Finocchiaro's body, according to the complaint.