Suspect in deadly Penn. trooper ambush described as 'very angry' survivalist
Officials display a mug shot of shooting suspect Eric Matthew Frein [NBC News]

Pennsylvania state police on Tuesday identified Matthew Eric Frein, described as an anti-law enforcement survivalist, as the prime suspect in the ambush of two troopers outside their barracks last week.

An arrest warrant was issued for Frein, 31, of Canadensis, Pennsylvania, on first-degree murder and seven other charges, State Police Commissioner Frank Noonan told a news conference.

“He’s armed and extremely dangerous,” said Noonan, who added Frein was believed to be on the loose with a .308-caliber rifle and scope.

The shooting late on Friday outside the Blooming Grove barracks, about 100 miles north of Philadelphia, killed Corporal Bryon Dickson, 38, and critically wounded Trooper Alex Douglass, 31. The officers were shot during a shift change.

A local resident walking a dog in the area found a partially submerged green Jeep in a pond in the woods about 2 miles from the barracks. A search of the vehicle turned up shell casings that matched those found in a sniper's lair discovered in woods overlooking the barracks.

Also found in the vehicle were Frein's driver's license, Social Security card, vehicle registration, a game commission range permit, camouflage face paint, flashlights, two empty rifle cases, military gear and information about foreign embassies, according to the court documents seeking the arrest warrant.

A search of his parents' home in Canadensis, where police said Frein was living, turned up matching shell casings and a book titled "Sniper Training and Employment," the documents said.

Frein's father, a retired U.S. Army major, told investigators he had trained his son to shoot and described him as an excellent marksman who "doesn't miss," the documents said.

Two firearms were missing from the family home, including the rifle and an AK 47, Frein's father told investigators.

“Mr. Frein will be the top manhunt in the United States. Every law enforcement agent in this country is looking for this guy,” Noonan said.

Several people who knew Frein - described as 6 feet, 1 inches tall, 165 pounds, with blue eyes - said he had made statements against law enforcement and advocating mass violence, Noonan said.

"He is very angry about things going on in society," he said.

Douglass has been recovering after surgery and has been speaking with investigators, police said.

Blooming Grove is a township of about 5,000 people in the Pocono Mountains near Pennsylvania's border with New York.

(Reporting by Joe McDonald. Editing by Barbara Goldberg, Susan Heavey, Peter Cooney and Mohammad Zargham)

Watch footage from Tuesday's press conference, as posted by NBC News, below.