Cadaver dogs led authorities to a "common grave" where they found the body of one of four men who had been missing in suburban Pennsylvania since last week, Bucks County district attorney Matthew Weintraub said.
At a midnight news conference, Weintraub identified the man as 19-year-old Dean Finocchiaro. He was found in what was described as a 12.5 foot deep common grave in a sprawling property at the center of the investigation.
"We are not done yet. This is a homicide, make no mistake about it," Weintraub told reporters.
Additional human remains were found inside the grave, but were not yet identified, Weintraub said.
Finocchiaro was last seen at about 6:30 p.m. on July 7.
"We are going to bring each and everyone one of these lost boys home to their families," Weintraub said.
About a hundred residents and reporters gathered at a shopping mall a few miles from the property waiting for updates about the missing men.
"We've been monitoring everything on Twitter. We wanted to be supportive and comforting for our community," said Wyatt McLeod who lives in Bucks County.
Finocchiaro and three other men between 19 and 22 years old went missing over several days last week within miles of each other.
The first to vanish was Jimi Patrick of Newtown Township. He was last seen at 6 p.m. on July 5 but he wasn't reported missing until the next day after he had no contact with friends or family.
Police say the 19-year-old also didn't show up for work. He was a beer-runner at a restaurant-bar in nearby Doylestown, CNN affiliate WPVI reported.
"He was on the shyer side, but you would get a smile out of him, a little conversation," bartender Jennifer Albrecht told WPVI.
Two days later, Finocchiaro, Mark Sturgis, 22, of Pennsburg and Tom Meo, 21, of Plumstead Township went missing.
Close friends Sturgis and Meo were last seen near the Doylestown area in Bucks County, CNN affiliate KYW-TV reported. Both young men didn't go to work on July 8, police said.
Meo's girlfriend told investigators that she had been texting with Meo on July 7 until just before 7 p.m. After that she had not been in contact with Meo, which was "out of the ordinary and not common," court documents said.
While a search for the missing men intensified, a 20-year-old from the area was arrested and accused of stealing and attempting to sell Meo's 1996 Nissan Maxima.
Data from a police license plate reader captured Cosmo DiNardo's pickup and Meo's car driving in Solebury Township within seconds of each other on July 7 at about 7:49 p.m., court documents said.
Meo's vehicle was found at a property owned by the DiNardo family, a day after authorities said DiNardo attempted to sell Meo's car to a friend for $500, according to a criminal affidavit.
The car was still registered to Meo and had not been legally exchanged. The keys and title to the vehicle were folded up and hanging on the wall inside the garage of the property, the affidavit states.
In addition, Meo is a diabetic, yet his diabetic life-saving kit was still in the vehicle, Weintraub said.
DiNardo was first arrested Monday on a charge of possession of a firearm, an offense dating to February that was not related to the missing men case, Weintraub said.
DiNardo was prohibited from possessing a firearm because he had a mental illness and had been involuntarily committed to a mental institution for inpatient care, court documents said.
A judge had dismissed the charge in May, but the Bucks County district attorney's office authorized police to reinstate and refile charges last month.
He was released Tuesday evening after his father paid 10% of his $1 million bail in cash, but by Wednesday DiNardo was arrested again.
This time, he's facing once count each of theft and receiving stolen property. His bail was set at $5 million cash after Weintraub argued he was a flight risk.
DiNardo may be the only person facing charges in connection with the case as of Thursday, but it's still unclear whether he knew or had contact with Finocchiaro or any of other three men who remain missing.
Fortunato Perri, Jr., an attorney representing the DiNardo family released a statement, CNN affiliate WPVI reported.
"As parents, Mr. and Mrs. DiNardo sympathize with the parents and families of the missing young men and they are cooperating in every way possible with the investigation being conducted by law enforcement," the statement said.
Local and state police as well as the FBI had embarked on an "all hands on deck" search of a 90-acre property in Solebury Township, an area north of Philadelphia.
For five days, the farmland owned by DiNardo's parents, Antonio and Sandra DiNardo, has been search by dozens of law enforcement officers on foot and by air.
"I am still encouraged by the pace of the investigation, but as you can imagine, it's just massive in scope," he said.
"Take the biggest (investigation) you've ever seen and multiply it by a million," Weintraub added later.
Large makeshift tents were set up across the property and investigative teams dug for evidence using large machinery.
Susan Mangano and her teenage daughters said this quiet community in Pennsylvania has not seen anything like this before.
"We live here, we pass by, we saw the helicopters," Mangano said. "As a parent, it's been sickening to watch this. I have kids this age. It's just devastating."
Before Thursday, Weintraub said they recovered important pieces of evidence about the missing men at that site and at other locations.