DiNardo, 20, has been charged with the theft of a 1996 Nissan Maxima belonging to one of the missing men, 21-year-old Thomas Meo of Plumstead.
DiNardo, of Wayland Circle in Bensalem, had a court hearing late Wednesday afternoon and bail was set at $5 million cash.
The judge said it was the highest bail she has ever set.
RAW VIDEO: Cosmo DiNardo arrives at Bucks Co. prison
DiNarodo's attorneys argued the D.A. knew already knew about the theft and should have brought the charges beforehand. They say the D.A.'s office just wanted something to keep DiNardo in jail.
The D.A. argued DiNardo is a flight risk and suffers from mental illness, which makes him a danger to the community.
While the defense tried to argue DiNardo wasn't a flight risk, doesn't have a passport, and has no prior criminal history, the judge sided with the D.A.
A preliminary hearing on the current charges is set for July 31.
Booking photo of Cosmo DiNardo from Monday's arrest
Also on Wednesday evening, the lawyer for DiNardo's parents, Fortunato Perri Jr., released a statement. It reads:
"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."
According to Bucks County District Attorney Matthew Weintraub, Meo's girlfriend told investigators she last heard from him through a text message on July 7. On July 8, Meo's family reported him missing to authorities.
On July 9, Weintraub said, DiNardo allegedly tried to sell Meo's Nissan to a friend for $500. Weintraub said investigators know who that friend is, but they are withholding his identity "for potential safety."
The vehicle was later found at a property belonging to DiNardo's family on Aquetong Road in Solebury Township. The title for the vehicle was unsigned, Weintraub said, indicating there was no legal exchange of ownership.
Investigators also allegedly found a diabetic kit inside the car. Meo is diabetic, Weintraub said, and is known to carry that "life-saving" kit with him.
DiNardo is charged with theft and receiving stolen property.
"I don't know it, but it's possible that this charge will be enveloped in a larger set of circumstances," Weintraub said. "I don't want to comment on that prematurely, though."
The other missing men are identified as Mark Sturgis, 22, of Pennsburg; Dean Finocchiaro, 19, of Middletown Twp.; and Jimi Tar Patrick, 19, of Newtown.
Like Meo, Sturgis and Finocchiaro were last seen on July 7. Patrick was last seen on July 5.
PHOTO: Identities of missing men
DiNardo was arrested on Monday after charges were re-filed for a weapons offense in February. He was freed on Tuesday evening after posting 10 percent of $1 million bail.
According to an affidavit of probable cause from the February incident, DiNardo was accused of possessing a shotgun and ammunition despite a history of mental illness that includes an involuntary commitment.
Weintraub also noted during the news conference that the massive search at the nearby farmland in Solebury Township, which is also owned by the DiNardo family, is intensifying.
"We are going to find something for sure, I have no doubt about that," he said. "I can't really confirm more."
News of DiNardo's arrest came just hours after Weintraub announced that several pieces of evidence had been recovered at several sites, including the farmland in Solebury Township.
"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 said.
Weintraub also said on Wednesday morning that no human remains have been found.
When asked if the evidence leads him to believe the remains of the four men were on the property, Weintraub simply said investigators are going to "continue in the direction that we're going."
"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 said.
The search for the four missing men stretched into its fourth day on Wednesday.
Video from Chopper 6 showed a search area with sections dug up by heavy equipment while tents covered portions of the scene.
Sources tell ABC News that a ping from one of the missing men's cellphones led investigators to the property.
Bucks County District Attorney Matt Weintraub earlier said he believes foul play is involved.
"I sure believe there is," he said during a news conference on Monday afternoon.
The FBI has joined the investigation. Weintraub said the leads in this case are "very hot."
"We've been treating this from the outset as a criminal investigation, and nothing has deterred that to this point," Weintraub said.
But when asked why he believes foul play was involved, he said it was due to "information that I know that I can't share."
Weintraub said it is believed all four men know each other, but investigators are working to confirm those details.
He said while "tons" of tips have come in, investigators continue their plea to the public for more information.
"What we're looking for is information that connects these four men together, that may connect them to the property we're searching, connect them to Cosmo DiNardo, perhaps," he said. "I can't say if there is that type of information, but if there is, I beg of you to please give it to us and let us run it down."
PHOTOS: Search in Bucks County for missing men
"Hope and pray for the best"
People who know the four missing men say all they can do now is hope for the best.
Jennifer Albrecht is a bartender at the Candlewyck in Doylestown, where Jimi Patrick works as a beer-runner.
She says Jimi is one of the nice guys.
"He was on the shyer side, but you would get a smile out of him, a little conversation," she said.
Albrecht says the irony is how this shy, soft-spoken young man is now at the center of most conversations at the bar.
"Everybody's talking about it. Everybody just wants to find all four of the men that are missing," Albrecht said. "Hope and pray for the best. For all of them."
Anyone with information is asked to contact investigators at 215-297-8201. null