Pennsylvania State Police have identified Eric Matthew Frein, 31, Canadensis, as the man they believe killed a trooper and critically wounded another outside a rural barracks. Cpl. Bryon Dickson, 38, was shot and killed outside the Blooming Grove barracks in northeastern Pennsylvania late Friday. Authorities said earlier Tuesday they had made progress in their effort to catch the rifle-toting gunman, obtaining a search warrant connected to the late-night ambush. The office of District Judge Michael Muth confirmed a search warrant was issued early Tuesday. The judge, based in a neighboring county, declined to provide a copy of the warrant or release any details about the location of the search. Investigators planned a Tuesday afternoon news conference. The assailant, using a .308-caliber rifle, opened fire during a shift change. The motive is unknown, but police have said it's likely the gunman had a grievance against the state police. Authorities released a likely profile of the gunman on Monday in hopes it might help authorities catch him. The profile indicated the gunman might be an avid hunter or received firearms training -- possibly from law enforcement or even the military. It also suggested he regularly visited a shooting range to keep his skills sharp and made several trips to the barracks, picking just the right hiding spot from which he could launch an ambush and make his escape. Lt. Col. George Bivens vowed Monday that police would arrest the "coward" who "did it from a place of hiding and ran." Bivens said: "The act that you committed may have been meant as an act of intimidation. It has not intimidated us. The Pennsylvania State Police is committed to bringing you to justice. We will find you and we will seek justice when we do." Police received hundreds of tips as a nonprofit group increased its reward offer to $75,000 for information leading to the gunman's capture, and a number of the tips provided "credible information" about the ambush, Bivens said. Pennsylvania Crime Stoppers has asked anyone with information to call them or submit tips online. Trooper Tom Kelly, a state police spokesman, said in a statement earlier Tuesday that parts of Route 402, a roadway that runs through a forest near the barracks, were blocked overnight to allow a search of the area without endangering the safety of motorists. He didn't say what investigators were looking for but said the road was reopened and no one was in custody. As the manhunt continued, Dickson's family prepared for his funeral, to be held Thursday at a Roman Catholic cathedral in Scranton. Dickson, a Marine Corps veteran who joined the state police in 2007 and had worked as a patrol unit supervisor in the Blooming Grove barracks since June, is survived by his wife of 10 years and two young sons. The injured lawman, Trooper Alex Douglass, a nine-year veteran, was conscious and talking for the first time since he underwent surgery. Investigators planned to interview him.