Earlier Thursday, investigators worked to excavate a 12-foot grave found to hide human remains on the 90-acre farm. Lang says prosecutors agreed to take the death penalty off the table in return for DiNardo's cooperation.
Investigators are searching multiple locations for clues to the whereabouts of the men, one of whom went missing last Wednesday and the others on Friday, he said.
Cadaver dogs led authorities to the remains of Dean Finocchiaro, 19, after he and three other young men went missing late last week. Sturgis and Meo are last seen that day, as is Dean Finocchiaro, 19, of Middletown Township.
Bucks County District Attorney Matthew said in a midnight press conference that Finocchiaro was found in a "common grave", 12.5 feet under the ground.
Weintraub said at a news conference on Wednesday, "I feel that we bought ourselves a little bit of time in charging Mr. Dinardo with the stolen auto case today", and he referenced that Dinardo's bail had been set at $5 million.
A 90-acre property on Route 202 in Solebury Township is the main search site in the case of four missing Bucks County men.
Now that man has confessed to killing the four victims.
According to an arrest affidavit obtained by PEOPLE, DiNardo is not allowed to possess weapons because he had previously been involuntarily committed to a mental institution.
Other human remains were found in the same deep pit.
DiNardo reportedly apologized as he left the courthouse on Thursday afternoon.
The person with knowledge of the confession said one of the men was killed July 5 and the other three were killed July 7.
DiNardo was initially arrested on Monday on charges relating to illegal possession of a shotgun and ammunition. According to the Times, police also found Sturgis' vehicle at an outdoor shopping mall.
The Associated Press, citing a person with firsthand knowledge of his confession, reported the DiNardo had a co-conspirator. Meo's 1996 Nissan Maxima is found in a garage on another property owned by the DiNardo family.
He is being held in the Bucks County jail on $5 million cash bail. The DiNardo's also own a home in Bensalem Township and own a concrete contracting company.