The 31-year-old survivalist who allegedly stalked and shot two state troopers last month in rural Pennsylvania has slipped past more than 1,000 troopers in the Pocono Mountains. The month-long manhunt has turned up little more than empty cigarette cartons and soiled diapers — until now.

Authorities uncovered what they describe as Eric Matthew Frein’s handwritten notes Sept. 29 at a campsite, along with explosive devices, ammunition, food, water and clothing. The writings were waterlogged, but police were still able to make out what they call a “cold-blooded and absolutely chilling account” of what happened Sept. 12 when he allegedly killed Cpl. Bryon Dickson and seriously wounded trooper Alex Douglass in Blooming Grove, Pa.

“I can only describe Eric Frein’s actions as pure evil,” State Police Lt. Col. George Bivens said Wednesday during a news conference.

The passage Bivens read started with a description of Dickson’s death.

“Got a shot around 11 p.m. and took it,” he wrote. “He dropped. I was surprised at how quick. I took a follow-up shot on his head, neck area. He was still and quiet after that.”

“Another cop approached the one I just shot,” he continued, explaining how Douglass entered the scene. “As he went to kneel, I took a shot at him and he jumped in the door. His legs were visible and still.”

Then Frein allegedly ran to his vehicle and quickly sped away.

“I ran back to the jeep,” he wrote. “I made it maybe half-a-mile from the GL road and hit a road block. I didn’t expect one so soon — it was only 15 to 20 minutes. I did a k-turn [three-point turn] a quarter mile from them and pulled into a development I knew had unfinished access roads. Hearing helos [helicopters], I just used my marker lights, missed the trail around a run off pool and drove straight into it.”

Authorities found Frein’s Jeep at the bottom of a swamp a few miles from the scene. Police said he fled from there and escaped into the hills about 15 or 20 miles away.

“Disaster,” he wrote, recounting the get-away. “Made half-attempt to stash AK and ran.”

Police initiated the manhunt, ordered a lockdown in the area and entered the woods, clad in bulletproof vests and armed with rifles.

“We know that Frein has prepared and planned extensively for months, and maybe years,” Bivens said. “He planned his attack and his retreat.”

On Wednesday, Bivens said the journal did not indicate that Frein knew either of his victims. Frein does not mention either one by name.

Frein of Canadensis, Pa., has been charged with homicide and attempted murder. He is also is wanted for unlawful flight to avoid prosecution. Authorities added two additional charges on Wednesday for possessing two weapons of mass destruction.

Since last month, he has been playing hide-and-seek with law enforcement, leaving a trail of trash, including dirty adult diapers. The FBI said DNA testing on the diapers was inconclusive since they had been exposed to the elements.

On Tuesday, police caught another glimpse of him — just 200 yards out of reach. Tactical teams have also uncovered evidence he hid out and built small fires in nooks in a 40-foot rockface, Bivens said.

“We will get Frein,” he said. “Whether that is today, whether that is tomorrow or whether that is next week remains to be seen.”