An attorney representing the couple issued a statement saying they sympathize with the families of the missing men and are cooperating "in every way possible with the investigation".
"We have now received the official announcement of the death of Jimi Patrick, Class of 2020".
Dinardo, whose parents own the Solebury Township farm being searched, was already in custody after being accused of stealing and trying to sell a vehicle belonging to one of the missing men.
DiNardo, who had run out of ammunition, then used the backhoe to run over Meo and haul all three bodies to one spot where they were buried in a common grave after he tried to burn the remains.
Using a backhoe, DiNardo then dug a hole to place Patrick's body into, the complaint said.
On Wednesday, police arrested a young man whose parents own the farm on a charge he tried to sell a auto belonging to one of the missing men.
Prosecutors said DiNardo suffered from schizophrenia.
"I don't know how this is going to end up, unfortunately, but I am confident that we are going to get to the bottom of this", Weintraub said.
"I'm not sure", he said, "we could ever answer that question".
"I don't understand the science behind it, but those dogs could smell these poor boys 12½ feet below the ground", Bucks County District Attorney Matthew Weintraub told Fox News.
Dinardo and Kratz were apparently on the illicit trade of marijuana and firearms.
A man who confessed to killing four Pennsylvania men who disappeared last week has been charged with four counts of homicide while a second man has been accused of participating in three of the slayings.More news: Unanimous Advice To FDA: Approve Landmark CAR-T Cancer Therapy
DiNardo might have been released, but still he remains a person of interest.
DiNardo told authorities the killings began July 5 after he agreed to sell four pounds of marijuana for $8,000 to Jimi Patrick, 19, a fellow student studies at Catholic High School the first victim. He says Kratz shot Finocchiaro during the robbery.
He admitted to being with his cousin when they agreed to rob Finocchiaro and picked him up. Both men walked to a remote area of the property, where DiNardo allegedly said he fatally shot Patrick with a.22 caliber rifle, according to the affidavit. Finocchiaro's body was then placed in a blue tarp and he was tossed into the pig roaster.
Meo's grandfather, Chuck Meo, told an NBC News producer that crews found the remains under a blue tarp after lifting out a propane tank, WCAU-TV reported. Sturgis, meanwhile, started to run away as DiNardo started shooting at him. Then he led the police to the crime scene. He put them in the same metal tank as Finocchiaro and poured gasoline in it and lit it.
The recovered auto was found on a second DiNardo family property about a half mile from the farm. They have a construction company and cement.
Asked whether DiNardo's information was critical to finding the body, the district attorney told reporters: "We'd still be looking, I know that much".
While authorities said they're making progress in the search, Weintraub also said foul play is suspected in the disappearances.
Authorities had charged DiNardo earlier this year with having a gun despite an involuntary mental health commitment.
The original charge was dismissed by a judge in May, and the Bucks County district attorney's office authorized police to reinstate and refile that charge on June 21.
Finocchiaro and the three others went missing over several days last week within miles of each other.
He had been previously held on a $1 million bond until Tuesday evening for an unrelated weapons charge.