State police declined to comment Monday on reports that authorities found a handwritten letter believed to be penned by accused cop killer Eric Matthew Frein.

Citing anonymous sources, both CNN and ABC reported Monday that the letter, found during the manhunt for Frein, details how he allegedly shot two officers during the Sept. 12 ambush at the Blooming Grove state police barracks in Pike County, and then escaped.

State police would not confirm or deny the networks' reports.

"I am not commenting on evidence found unless it poses a threat to the community," said state police spokesman Trooper Tom Kelly in an emailed statement Monday. "I understand some networks are reporting information obtained through sources. This is the only official source and I cannot confirm anything reported by 'sources.'"

CNN reported the letter details how Frein allegedly evaded police and got around police checkpoints. The network cited two senior law enforcement officials in Pennsylvania as its sources, and reported that details in the letter are what led authorities to believe Frein wrote it.

ABC, citing a law enforcement official familiar with the case, reported the letter was found in the woods, and that authorities are unsure if the letter was left on purpose or by accident.

The letter does not provide a motive for the shooting death of Cpl. Bryon K. Dickson II, 38, of Dunmore, and wounding of Trooper Alex T. Douglass, 31, of Olyphant, and it is not clear when it was written, both networks reported.

The letter is the latest evidence found by authorities. On Friday, state police said they found a campsite where Frein, 31, of 308 Seneca Lane, Canadensis, had stashed food, ammunition, clothing and other supplies. Police have also found an AK-47, two "fully functional" pipe bombs, soiled diapers and empty Serbian cigarette packets in the manhunt. There is not conclusive evidence that the diapers belong to Frein, sources told The Times-Tribune last week.

Frein, who police say is the only suspect in the ambush, has been spotted several times, police said, but continues to evade capture because of the dense woods. Authorities also said he tried calling his parents. The call, which authorities said wasn't answered, redirected the massive manhunt to Monroe County.

Monday marked the 24th day since the barracks ambush. Search efforts have largely concentrated on a five-mile zone straddling Barrett and Price townships, near the Delaware State Forest and Frein's Pocono Outpost home, where he lives with his parents.

Monday's manhunt focused on a perimeter near the last known possible sighting of Frein.

FBI agents with assault rifles stood along State Route 447 just north of Clarks Road and Mill Creek Road, looking north into the Todd Price Nursery, a tree farm that extends for about a mile.

On Sunday, an intense police presence swarmed the nursery after a report of a possible sighting of Frein. Several search teams swept through the area while multiple helicopters circled overhead.

The details surrounding Sunday's sighting were not clear, but nearby resident Judy Baldaccini told The Times-Tribune there has been at least one incident in the last week where a cabin in that patch of woods appeared to have been broken into. State police said Frein may try to break into cabins or vacant homes to seek shelter.

Teams searched the woods in pockets all over the zone Monday, but Frein, who is considered armed and dangerous, remained a fugitive.

A group of three troopers emerged from the woods onto Bear Town Road on Monday, after another check of the forest floor and visual sweep of the tree branches.

It's a numbers game, one trooper said while waiting for a state police vehicle to take him to another patch of woods to search. Sooner or later, one sweep will find him, he said.