Person of interest in disappearances of 4 young men arrested for 2nd time Cosmo DiNardo, 20, was arrested Wednesday on a stolen property charge.

 -- The man considered a person of interest in the disappearance of four young men in Pennsylvania has been taken into custody for a second time, this time on a stolen property charge related to the missing men, authorities said.

Cosmo DiNardo, 20, was arrested Wednesday on a charge related to a 1996 Nissan Maxima, which authorities believe belonged to one of the missing men, 21-year-old Tom Meo, Bucks County District Attorney Matthew Weintraub said in a press conference Wednesday afternoon.

DiNardo's bail was set to $5 million in cash, the highest that Bucks County Magisterial District Judge Maggie Snow has ever set, she said.

Weintraub said before DiNardo's arraignment Wednesday that he intended to argue a "very, very high bail" on the new charge, adding that he believes DiNardo to be "even more of a flight risk at this point."

Meo's girlfriend told authorities that he went missing on Friday, and he was reported missing by his family on Saturday, Weintraub said. On Sunday, DiNardo allegedly attempted to sell the car for $500, Weintraub said.

Meo's diabetic kit, which he "never went anywhere without," was still inside the car, Weintraub said. DiNardo is expected to be arraigned today.

A statement from the attorney representing the DiNardo family, Fortunato Perri Jr., said DiNardo's parents are cooperating with law enforcement.

"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," Perri said.

Investigators have uncovered what they call key clues at a property in southeast Pennsylvania as the search continues for four young men who have been mysteriously missing for days.

At a press conference Wednesday morning, Weintraub said authorities have "not yet recovered any human remains" that he can report to the media, but they have found "several important pieces of evidence" on the property in Bucks County, which is about 40 miles northeast of Philadelphia.

"We have recovered several important pieces of evidence at this site that we’re currently working very hard on with the majority of our manpower and at other locations," Weintraub told reporters. "This is just really, really rough on everybody involved because of the heat, the magnitude, the scope and the stakes are incredibly high -- life and death."

Weintraub couldn't provide any further details on the evidence they uncovered at the property, only adding, "We are encouraged by it and we are going to keep going."

"We're going to keep digging and searching that property until we're satisfied that they are not there," he told reporters.

Jimi Tar Patrick, 19, of Newtown Township, has been missing since Wednesday, while Mark Sturgis, 22, of Pennsburg, Dean Finocchiaro, 19, of Middletown, and Meo, of Plumstead, all disappeared Friday.

Weintraub has said the relationship between the four young men is not clear. But Sturgis' father "has said that his son and Meo are longtime friends who work in construction for him" and that "Finocchiaro is a mutual friend of theirs," according to The Associated Press.

Meo’s family also told authorities that he is good friends with Sturgis, according to a police criminal complaint filed today. Sturgis told his family he was going to meet with Meo on the day he went missing, the document states.

Sturgis did not show up for work on July 8, and he was then reported missing by his parents, according to the complaint.

Investigators fear the men may have been victims of foul play.

DiNardo was previously taken into custody on Monday on a charge stemming from illegally possessing a shotgun and ammunition in February. On Tuesday, he was named a person of interest in the men's disappearances.

Although investigators have been combing through all of Bucks County in connection to the men's disappearances, the main site being searched is a vast stretch of property owned by the DiNardo family. Sources told ABC News a cellphone ping is what led authorities the property, though Weintraub has said he can't say what directed authorities there.

Weintraub has said the search at the DiNardo property is massive and involves major construction equipment, fine sifting equipment and cadaver dogs.

"We are going to find something for sure I have no doubt of that," he said.

DiNardo was in jail being held on a $1 million bond in connection to the firearms possession allegation because he is considered a flight risk, not due to the men’s disappearances, according to Weintraub. The Bucks County District Attorney's Office announced Tuesday night that he had been released on bail, 10 percent of which was paid in cash.

"'Person of interest' I think is actually a media term, and I've adopted it at least for convenience sake. But this investigation is still wide open. We're going to go where it leads us," Weintraub said at the press conference Wednesday. "As of this moment, he remains a person of interest, but if others arise and we can name them, we will."

It is unclear if DiNardo has entered a plea in either charges against him.

ABC News' Shauna Beni, Aaron Katersky, Eva Pilgrim and Emily Shapiro contributed to this report.