CANADENSIS, Pa. - The search area for Eric Frein has shifted daily, with nearly 1,000 law enforcement officers scouring the Poconos woods.

Helicopters buzz overhead, and armored vehicles patrol the streets.

When residents leave their homes, they cannot be certain whether they will be able to return.

Yet the alleged killer of a state trooper continues to evade the police.

"I'm surprised the manhunt is going on this long," said Erik Kulick, who runs a wilderness survival school in Pittsburgh. "This guy, on the one hand, has to survive. What makes this difficult, presumably, for him is, he also has to evade."

It has been 16 days since Frein, a self-styled "survivalist," allegedly shot two troopers and fled into the woods. Investigators believe Frein is still in a roughly five-square-mile area in Monroe or Pike Counties, but they have provided few details about their progress in the last several days.

"Smaller search teams have expanded their search efforts to different areas, but the overall perimeter hasn't changed," said Trooper Tom Kelly.

The search areas through the dense woods appear to have shifted daily. With troopers on foot and armored vehicles Monday, a day after police focused on a wooded neighborhood bordering a state forest, the focus rapidly moved miles away, back near the main intersection of this village.

Normally a quiet crossroads with a few stores and a church, the intersection was suddenly filled with flashing lights and troopers with guns and binoculars.

It was unsettling for residents but also a reminder of the current reality in their rural community.

"This has been nothing but a Wild West show," said Lenny Castellano, sitting in a folding chair outside his auto repair shop and shouting over the buzz of the helicopters.

Kulick, the survival expert, said he teaches people to handle emergencies in the wilderness. But many of the same techniques would apply to Frein's retreat into the woods.

"Mental attitude. That's always the first priority," Kulick said.

Frein must have access to water if he is still in the woods, Kulick said, because people can only survive about three days without it. People can last three weeks - or longer - without food.

Kulick said he does not identify with so-called survivalists, the description investigators have associated with Frein. Survivalists are known to focus on stockpiling supplies and weapons, he said.

But Robert Ferreira, a survivalist who sells survival gear and lives in Northampton County - also in the Poconos but about 30 miles from the manhunt - said he is disappointed that police have described Frein as a survivalist because it places all survivalists "in a negative light."

Ferreira said he and many other survivalists use weapons for target practice and emergency preparation, and would never use them for violent attacks.

Frein, 31, is accused of killing Cpl. Bryon Dickson and wounding Trooper Alex Douglass at the state police barracks in Blooming Grove on Sept. 12. Police said he then retreated into the woods near his parents' home, about 20 miles from the scene of the shooting. Police said Frein likely prepared for years, and built a bunker in the woods to stockpile supplies.

As the search stretches into a third week, residents have returned to work. School buses resumed running in the Pocono Mountain School District on Monday, and the district said the manhunt would no longer be an excuse for absences and missed assignments.

Paul Hilfiger, a plumber in Barrett Township, said he had continued business as usual during the search. He has, at times, been stopped by police on his way to a customer's home. A few days ago, he was called to repair a toilet in a mobile FBI unit within the search area.

"I think that anybody that's really annoyed by this, picture it being their father or brother that was shot," Hilfiger said as he stopped by the Mountainhome Diner for a lunch of soup and coffee.

The diner, where customers greet each other and the employees by name, was mostly quiet at lunchtime Monday.

At 12:30 p.m., just three booths were full. The waitresses sang "Happy Birthday" to one diner, who said he had been up all night as helicopters circled his home. Another woman came in to eat because armed troopers were searching her backyard, and police advised her to stay out of her house.

Ferreira said it was difficult to guess how long the manhunt could continue.

"If he has the skills, then it's not surprising that they haven't found him yet," he said. "Given the nature of the Poconos, he could be anywhere."