Police on Wednesday added two felony counts of possession of weapons of mass destruction to the first-degree murder, homicide of a law enforcement officer and attempted murder and related charges accused trooper killer Eric Frein already faces.

The charges stem from the discovery of two pipe bombs, rigged with tripwires and studded with metal shrapnel, police found on Sept. 29 at what they say is one of the campsites Frein made in the heavily wooded area of Barrett and Price townships, Lt. Col. George Bivens said Wednesday. U.S. Bureau of Alcohol, Tobacco and Firearms Agent Sam Rabadi spoke at the press conference Wednesday, saying the pipe bombs were "complete and functional."However, Bivens said, the tripwire was not stretched.Also found were several pages of notes police say detail Frein's Sept. 12 fatal shooting of Cpl. Bryon Dickson and the grave wounding of trooper Alex Douglass at the Blooming Grove barracks in Pike County.The notes were in a garbage bag found with the pipe bombs and other items on Sept. 29 at a campsite police say Frein hastily left as he fled police. The notes did not indicate that Frein knew either Dickson, whom he killed, or Douglass, whom he seriously wounded, Bivens said.Bivens read aloud excerpts from the notes, which were several pages long."After reading this cold-blooded and absolutely chilling account, I can only describe Eric Frein's actions as pure evil," he said.The search for Frein, now in its fourth week, so far has cost millions of dollars for state police alone, Bivens said.While he could not give specific figures of the cost, he said the number of millions of dollars is in the single-digit range.He justified the amount, saying Frein "may well strike again.History has shown that that is frequently the case if the individuals involved are not apprehended."The Pennsylvania State Police didn't pick this fight," Bivens said. "But it is ours to finish."Rabadi concurred."Frein is a fugitive whom we believe is armed with a sniper rifle and explosives," he said."He is an existing threat, not only to law enforcement, but also to the community as a whole. Collectively, we will not stop until Frein is captured, brought to justice, and allow the citizens of this community to return to a sense of normalcy."Bivens said that since last Friday, there had been four sightings of Frein by residents and police.The last one, on Friday, from 175 to 200 yards, was by a police officer.However, thick brush and fading daylight prevented police from closing in.Bivens said police are confident the man seen is Frein because of clothing, body build and other markers.Frein, 31, is a self-styled survivalist and expert marksman who devoted a great deal of time and effort in playing military games and portraying soldiers.Police have at least twice searched the home Frein shared with his parents.Rabadi said police found a variety of black, smokeless and synthetic powders, along with other materials in Frein's bedroom, and said they link Frein to the two explosive devices found at the campsite.Police also seized a computer to which Frein had access and found searches for "can police track cell phone" on May 3, 2013;" "swat raid tactics" on April 29, 2013; "police raid training" on April 29, 2012; and "police manhunt guide" and "how to escape a manhunt," both on May 8, 2013.He also searched for tips on caching food and placing cached food on May 14, 2013, for information on a ballistics trajectory calculator on Nov. 7, 2012, according to an affidavit of probable cause.Subsequent searches revealed a list of items Frein packed to take with him as he fled police.As police comb the rugged woods in a several-square-mile swath around Frein's home, they've discovered makeshift campsites they believe were hurriedly left by Frein.They've found several items at the site in Price Township, including Frein's checkbook, a cellphone, food, clothing, a water bottle, a bag of garbage, 99 rounds of .308 ammunition marked AFF-88 and kept in an olive-drab pouch, the two explosive devices, a camouflage tarp, and camouflage netting.DNA on the water bottle and pouch was determined to be Frein's.At about 2 p.m. Sept. 18, Frein was in Price Township, about 3 miles from his home, according to electronic surveillance of the cellphone.Bivens said small campfires and other sites indicated that Frein may have been hiding on a shelf of a rock cliff in the woods.Police are confident Frein is still in the rugged wooded area within several miles of his home.