BLOOMING GROVE TWP. - Eric Matthew Frein has been added to the FBI's 10 Most Wanted list.

"This will make the world where he can hide a very, very small place," Edward Hanko, special agent in charge of the FBI office in Philadelphia, said at a news conference Thursday afternoon.

Anyone with information is urged to call a tip line, 1-866-326-7256.

Frein is suspected of ambushing Cpl. Bryon Dickson as the state police officer left the Blooming Grove barracks shortly before 11 p.m. last Friday.

Dickson was fatally shot with a .308 rifle.

Another trooper, Alex Douglass, was critically wounded in the shooting but is recovering.

The reward for the capture of Frein has been increased to $175,000 - $100,000 from the FBI and $75,000 from Crimestoppers.

Investigators are "fairly confident" that the suspect is still in the area, probably in woodlands, said state police Lt. Col. George Bevins. He would not elaborate on why investigators believe that.

State Police Commissioner Frank Noonan said, "We think he's here but we are looking everywhere."

Bevins said, "I do believe (Frein) is probably desperate," but noted that the suspect is still believed to be armed and dangerous.

Investigators said Frein has changed his hairstyle, which is now shaved on the sides.

Authorities are "systematically" taking away areas where the suspect may be holed up, such as cabins in wooded areas of Blooming Grove Township.

They do not believe he is being aided by anyone at this time.

Bivens said the FBI designation will help investigations in their pursuit and he believes the suspect will be caught.

Noonan said just because Frein is suspected of committing a cowardly crime, his parents are devastated and victims as well and have been fully cooperating in the investigation.

Crime is "not contagious to family," said the state police commissioner.

Frein is described as a self-taught survivalist who is an expert marksman.

Bivens noted that authorities have enlisted investigators who are trained in woodland searches.

Noonan said hundreds of investigations are on the case and they have been receiving an "awful lot of calls."

Authorities urge the public to use common sense and report sightings or any suspicious activity.

The public in the area also is urged to keep vehicles and houses locked.

Frein is described as a war re-enactor enthusiast who has traveled to Europe for training in paramilitary activities.

Authorities were alerted to Frein after his parents' vehicle was found stuck in a waterway in the woods near the state police barracks.

His drivers license and Social Security card were in the vehicle, police said.