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EXCLUSIVE DETAILS: Pennsylvania State Police say they believe fugitive escapee Michael Burham is receiving outside assistance in the interstate manhunt that began Thursday night after he slipped out of the Warren County jail and was believed to have run off into the forests along the border of Pennsylvania and New York.

Burham, an Army veteran with survivalist and firearms training, was being held on kidnapping and related charges and is also suspected of murder and rape in New York in an interstate crime spree that ended in his arrest in South Carolina after a previous manhunt in May.

He made his way though the jail's gym to the rooftop Thursday night, where he was able to climb down with a rope made from bedsheets, according to authorities. Then he snuck off in a denim jacket and jail issued orange-striped jumpsuit and matching Crocs at around 11:20 p.m., police said. But he may have changed his clothes along the way, and more than 150 officers from state, local and federal agencies were looking into reports of possible sightings in both states.

"We do believe that he is getting some assistance," Pennsylvania State Police Lt. Col. George Bivens revealed during his remarks Monday afternoon. "We are prepared to prosecute anyone who does offer him assistance."

MANHUNT LAUNCHED AFTER MURDER SUSPECT WHO WROTE HE'S 'NOT SORRY' ESCAPES PENNSYLVANIA JAIL

Michael Burham in a mugshot, victim Kala Hodgkin in an undated family photo

Michael Burham is accused of shooting Kala Hodgkin to death in New York before lighting another woman's care on fire and then kidnapping a Pennsylvania couple, according to police. He escaped custody Thursday night, prompting a new manhunt. (Cattaraugus County Sheriffs Office | Kala Hodgkin/Facebook)

Burham should be considered armed and dangerous, Bivens said, and authorities believe he is still in Warren County or one of its surrounding areas. 

Police have been on his trail since early Friday and previously told Fox News that they'd uncovered a series of possible campsites in the area and did not believe the suspect had traveled far.

Police have also investigated several burglaries and break-ins in the surrounding area, including an incident in which a Western New York couple's dog was found dead and clothes were stolen from their home. But Bivens said police had not found a direct association with any of the incidents and Burham's movements.

FUGITIVE WANTED FOR SEX ASSAULT, KIDNAPPING IN ALLEGED MULTISTATE CRIME SPREE NABBED AFTER ‘DAYS-LONG MANHUNT’

Michael Burham in orange striped jail jumpsuit for mug shot

Authorities are searching for Michael Burham, described by police as "very dangerous." He was a suspect in a homicide investigation and was being held on $1 million bail on kidnapping, burglary and other charges, authorities said. (Warren City Police Department via AP)

The suspect has numerous relatives in the area, but police declined to comment on whether his family was cooperating.

"At some point we will force him to make a mistake, and when he does, we will use that to our advantage," Bivens said. 

U.S. Marshals joined the manhunt Saturday, announcing a reward of up to $9,500 for information leading to his capture.

Burham spent more than 11 years in the Army Reserve as a water treatment specialist and utilities equipment repairer, from February 2008 to December 2020, Fox News has learned.

He was never deployed and was a sergeant at the end of his service, according to the Army.

MANHUNT FOR ESCAPED PENNSYLVANIA JAIL INMATE, MURDER SUSPECT CONTINUES

But in May, he was suspected in a shocking crime spree that involved the shooting death of a New York woman he had been separately accused of raping and the abduction of a Pennsylvania couple who were later found in South Carolina.

Michael Burham wearing a hat and backpack in the woods

Burham is accused of a sexual assault in Jamestown, New York, and the kidnapping of an elderly couple in Pennsylvania, whom he allegedly drove to South Carolina before releasing them, unharmed, the FBI said. (FBI)

Police said they considered Burham armed and dangerous.

Jamestown police found Kala Hodgkin, 34, shot dead in her home early on May 11, according to federal court filings. She had three children, ages 8, 11 and 14, according to a GoFundMe campaign set up by friends and family.

That same day, Burham was allegedly recorded on his ex-girlfriend's Ring doorbell camera trying to break into her house and lighting her car on fire.

He is believed to have crossed state lines into Pennsylvania, where the couple was reported missing along with their car on May 20.

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Pennsylvania police sent out a missing persons alert, and South Carolina Highway Patrol found the victims alive the following day in North Charleston.

They told police they had been taken at gunpoint from their home and identified Burham as their alleged kidnapper, according to authorities.

Burham was arrested on May 22 after police tracked him to South Carolina, where they found a note to his father in a stolen car.

"I'm not sorry for what I did, however I do feel terrible about the children," the note reads, according to court filings.