The suspect involved in the death of a Pennsylvania state trooper in an ambush-style attack outside a barracks is a survivalist, “who has expressed a desire to kill law enforcement officers and commit mass murder,” the Associated Press (AP) reported.

Eric matthew Frein, 31, of Canadensis, Pennsylvania is still at large and armed with the .308-caliber rifle used to kill the trooper and injure another officer during the attack last week, said State Police Commissioner Frank Noonan at a press conference.

Noonan also called Frein “extremely dangerous.”

“He has made statements about wanting to kill law enforcement officers and also to commit mass acts of murder,” said Noonan. “What his reasons are, we don’t know. But he has very strong feelings about law enforcement and seems to be very angry with a lot of things going on in our society.

Frein was charged yesterday with first-degree murder, homicide of a law enforcement officer, and other offenses, according to the AP. Police officers from across the state are currently searching the rural area of Pennsylvania.

“We have no idea where he is,” said Comm. Noonan.

A resident in the area saw a vehicle “slightly submerged” in a pond and called police, who found shell casings in the vehicle that matched those found outside the barracks, said Noonan. They also found Frein’s Social Security card, camouflage face paint, a black hooded sweatshirt, two empty rifle cases, military gear, and a permit for a Pennsylvania Game Commission range.