BLOOMING GROVE, Pa. - Eric Frein's Internet searches included how to avoid police during manhunts, use law enforcement technology, and survive in the wilderness. That evidence, retrieved from a computer, suggests that Frein spent years planning an attack and retreat into the Pocono Mountains, a state police commander said Friday. Police believe Frein is still in the woods in Monroe or Pike Counties, two weeks after he allegedly killed one trooper and wounded another. It had been nearly three days since police last spotted Frein, but they said they have no evidence to suggest he has left the area. Lt. Col. George Bivens, who is leading the manhunt, said the clues they have gathered suggest that Frein sees the manhunt as "a war game," in which he is hiding in caves and abandoned buildings, angling for a fight with police. 
 
 "He is probably not going to come out and have a face-to-face confrontation," Bivens said at a news conference in the township building here. "I suspect that he'll be hiding and trying to take a shot from some distance from a place of concealment." 
 
 Bivens would not elaborate on the computer search that convinced them of the suspect's plans, but said the computer was not Frein's. Police said Frein removed the hard drive from his own computer. 
 
 Police believe Frein purchased materials to construct a bunker and stashed items in the woods before the shootings. They have yet to uncover a bunker but have found evidence that he has been in caves and abandoned structures. Bivens also said Frein may have a radio with him. 
 
 Bivens spoke hours after an old hotel in an upscale mountain neighborhood, abandoned since it closed in 1991, was briefly the focus of the search. 
 
 Frein was "familiar with" the 900,000-square-foot property, which includes the 400-room hotel and several other abandoned structures, said Trooper Tom Kelly. 
 
 Kelly said Frein had not been spotted on the property, and Bivens did not elaborate on whether police found any clues inside the building. He said tips and interviews led them to the site. Residents said that was no surprise; the old hotel is rumored to be haunted and is often explored by local teenagers and vandals. 
 
 The inn is surrounded by a community of weekend homes with a golf course, tennis courts, and swimming pool. 
 
 Investigators secured the perimeter of the property and spent 10 to 12 hours Friday morning searching the building in Barrett Township, Monroe County. They had vacated the area by early afternoon, leaving no trace of a search on the neighborhood's winding roads. 
 
 Investigators have not abandoned their other search area, where they have gone door-to-door speaking with residents and at times prohibiting them from leaving their homes. Armed troopers in camouflage, along with armored vehicles and helicopters, continued to survey the roughly five-square-mile area in Monroe and Pike Counties on Friday. 
 
 Troopers are surveying the woods with caution because they believe Frein may have explosives. 
 
 "We are aware that he may have experimented with those, and we are searching for those," Bivens said. 
 
 Bivens said sightings of Frein in that area have mostly happened around dusk. But he has been quite far away, and helicopters have had difficulty detecting him in the dense woods. 
 
 "We believe we had success in that, at least one occasion tracking with the dogs, was when we caused him to jump out at quite some distance out ahead of us and escape," Bivens said. "It was several days ago." 
 
 Police limited their search to the area near Freins' parents' home in Canadensis last week after he turned on his cellphone to call his parents, sources said. Bivens on Friday declined to comment on whether Frein has used a cellphone. 
 
 Frein, 31, is charged with killing Cpl. Bryon Dickson and wounding Trooper Alex Douglass outside the state police barracks in Blooming Grove on Sept. 12. 
 
 Douglass is hospitalized and is on a "slow but steady road to recovery," Bivens said. 
 
 Police have declined to speculate on a possible motive for the shootings but have said Frein is targeting law enforcement officials rather than the general public. 
 
 For the last two weeks, police say, Frein, a self-taught "survivalist" has been on the run in the woods, even taunting police by appearing at a distance and leaving behind items such as soiled diapers and Serbian cigarettes. 
 
 Sources familiar with the investigation said troopers also found a jacket and protein bar wrappers that may have belonged to Frein. 
 
 Bivens, who said he thinks Frein may have access to news through a radio, addressed the alleged killer directly on Friday. 
 
 "Eric, as I told you last week, you are a coward," he declared. "We will find you and we will bring you to justice." 

 Story highlights Eric Matthew Frein tried to call his parents earlier this month, source says 
 
 Frein, a self-styled survivalist, is believed hiding in the Pennsylvania woods 
 
 He is accused of killing one Pennsylvania state police officer and shooting another 
 
 A review of a computer hard drive used by cop-killing suspect Eric Matthew Frein shows he planned the attack and his retreat into the woods for a couple of years, Pennsylvania State Police Lt. Col George Bivens said Friday. 
 
 Bivens said a hard drive which Frein had access to indicated extensive Internet research on topics such as "how to avoid police manhunts, use of various law enforcement technologies and skills related to survival." 
 
 "It did give us a lot of insight into the techniques that he might be employing -- what his escape might involve," Bivens said. "But it did not provide as much information as we might have hoped had it been his own computer." 
 
 Frein, 31, is the suspect in a September 12 ambush that left Cpl. Byron Dickson dead and another trooper wounded outside the Pennsylvania State Police barracks in Blooming Grove, Pennsylvania. He is still being sought. 
 
 Police were able to track Frein through his cell phone when he called his parents one time earlier this month, a federal law enforcement official told CNN. Frein hung up after one ring, the source said. 
 
 Authorities asked CNN not to report Frein's cell phone use at the time. The detail can be reported now because police have identified the area where they believe Frein to be. The cell phone has not been turned on since that time. 
 
 The manhunt for accused murderer Eric Frein continues in Monroe County, Pennsylvania, for second week. 
 
 JUST WATCHED Filmmakers interviewed Eric Frein Replay More Videos ... MUST WATCH Filmmakers interviewed Eric Frein 06:30 
 
 "I'm not going to comment on anything that may have been done with cell phones," Bivens said Friday. 
 
 Direct message from police 
 
 Addressing Frein directly, the colonel said, "You are a coward. Your actions have caused tremendous disruption for an innocent community all while you try to hide from us. We are not intimidated. We will not leave ... We will protect the community. We will find you and we will bring you to justice." 
 
 The nearly two-week search for Frein included the abandoned Buck Hill Inn, a sprawling 46-acre hotel complex. 
 
 "Frein has been known to visit the area in the past and it is a large facility that needs to be cleared," Pennsylvania State Trooper Tom Kelly said via email. "There has been no sighting there or no one specific reason as to why it is being searched." 
 
 Bivens added, "We do know he has an interest in that location and do know he has spent some time there." 
 
 A war buff obsessed with Eastern European military conflicts, Frein has "experimented with explosives," Bivens said. "We are taking that into consideration" and checking for "booby traps" while searching cabins and caves where Frein might have been hiding. The suspect may have a radio with him. 
 
 "There is nothing in our investigation that indicates Frein has left the area," he said. 
 
 Suspect described as very meticulous 
 
 Frein appeared in an upcoming documentary about Vietnam War re-enactors called "Vietnam Appreciation Day." 
 
 "Eric kind of kept himself to the side," Patrick Bresnan, the director, told CNN's Anderson Cooper. "He had mannequins that he brought that he dressed in uniforms. He was very meticulous about the layout of those mannequins, the weaponry that were with them. He had magazines from the period, letters from soldiers back to their family and a lot of photography." 
 
 Bresnan said most re-enactors see what they do as a hobby. A small percentage, however, take the practice too seriously, even hoarding both antique and modern weapons. There is a sense of empowerment they feel re-enacting battles, he said. 
 
 "There is the point in which the fantasy of being a soldier kind of gets blurred and they become a soldier," he said. "And I think that's what we are seeing here with Eric." 
 
 Bresnan's wife, Ivette Lucas, who also worked on the film, said of Frein: "He was very specific, very precise about what he did. And he actually preferred to do what they call tactical re-enactments, which are re-enactments that are private and that are performed in the woods where they actually go out and hunt the, you know, in this case, Viet Cong... He might have just snapped and took the fantasy a little bit, well, way more seriously. " 
 
 On Wednesday, with as many as 1,000 law enforcement officers involved in the manhunt at any given time, authorities revealed that the meticulous, grid-like search over some 3 square miles of rugged terrain was paying off. 
 
 There have been a number of sightings of a man believed to be Frein by both residents and police, Bivens said without giving further details. 
 
 The sightings were from a significant distance, however. 
 
 The search has yielded an empty pack of Serbian cigarettes, Bivens said. Frein claims to have fought with Serbians in Africa and has studied Russian and Serbian languages, according to the FBI, which last week named him one of its 10 Most Wanted fugitives . Soiled adult diapers were also found, perhaps used by Frein to stay in a stationary position for long periods of time. 
 
 Authorities have said that Frein hated law enforcement and that they believe that he's solely focused on hurting more officers but not civilians. 
 
 Trooper Alex T. Douglass survived the shooting. 
 
 "I think this is a game to him in some ways," Bivens said of Frein this week.
– As authorities continue to search for a survivalist suspected in the shooting of two Pennsylvania state troopers, the trail—which has included diapers and cigarettes—has taken them to an abandoned hotel. Locals call the place, which hasn't been used this century, haunted, the Philadelphia Inquirer reports. A trooper says Eric Frein was "familiar with" the Buck Hill Inn in Monroe County, and officials secured the area today, but apparently didn't find Frein; they'd left by the early afternoon, the Inquirer notes. Meanwhile, more details about Frein are emerging. He was involved in Vietnam War re-enactments, and he's in a documentary about the subject due for release, CNN reports. Most re-enactors are hobbyists, but some are deeply invested in what they do, the director tells CNN: "There is the point in which the fantasy of being a soldier kind of gets blurred and they become a soldier," he notes, "and I think that's what we are seeing here with Eric." According to police, Frein has "experimented with explosives," and a search of a hard drive he used showed information on "how to avoid police manhunts, use of various law enforcement technologies, and skills related to survival." He likely planned the attack for two years, police note.