A suspect in the fatal ambush of a trooper has occasionally made himself visible to officers before melting back into the forest, and police found empty packs of Serbian-branded cigarettes and soiled diapers believed to have been left by him, Pennsylvania State Police said Wednesday.

Officers saw a man they believe to be Eric Frein as recently as Tuesday, Lt. Col. George Bivens said Wednesday afternoon. But it was at a distance, and the extremely rugged terrain separating the officers from Frein gave him “the ability to disappear,” Bivens told reporters.

It was the first time authorities have reported possibly laying eyes on the 31-year-old suspect charged with opening fire at the Blooming Grove state police barracks on Sept. 12, killing Cpl. Bryon Dickson and seriously wounding a second trooper who remains hospitalized.

Bivens said the discovery of the empty packs of cigarettes and dirty diapers is helping to cement authorities’ belief they were closing in as the manhunt stretched into its 12th full day. They believe Frein is using diapers so he can remain stationary for long periods of time. They are testing the diapers to confirm he wore them.

Frein appears to be probing the loose perimeter that’s been set up around him in a heavily wooded area around Canadensis, where he grew up and his parents still live, Bivens said.

He appears to have purposely made himself visible at times, staying just far enough away to make it unlikely he’d be caught, he said.

“I almost think that some of this is a game to him,” Bivens said.

Upwards of 1,000 law enforcement officials have been involved in the search for Frein, named last week to the FBI’s 10 most wanted list. He is considered armed and dangerous, and police have authority to kill him if he doesn’t surrender.

In an indication of just how wild the landscape is, tactical teams have “kicked out quite a few bears” as they search for Frein in caves, Bivens said.

The lengthy manhunt has upended life in this usually tranquil corner of the Pocono Mountains, with unannounced and indefinite roadblocks and a “shelter in place” directive that prevented residents from leaving their houses for more than 24 hours at one point. Those who weren’t already home could not return.

Residents say they support police in the search for Frein, but patience is wearing thin.

“Families are getting separated,” said Adam Christmann, who has been kept from his home at least twice in the past few days.

High school student Kendall Lewczak left home at 7 a.m. Friday to go to work with her mom, since classes had been canceled because of the manhunt. They came back in the late afternoon to find access to their street blocked off.

“We spent the night over on the bridge sleeping in the car waiting, and hoping, that we could get home,” Lewczak said.

Authorities insist residents have been able to get escorts to their homes in emergencies, such as to retrieve medication. But some residents said elderly relatives have been left unattended and pets unfed.

One attorney accused police of violating residents’ rights, and urged anyone who felt aggrieved to contact him.

“Just because one of their brethren was murdered does not give them a right to violate YOUR Rights,” Joshua Prince of Bechtelsville wrote on his firm’s website.

The provocative post, coming less than two weeks after Dickson’s death, drew hundreds of comments, split between those calling Prince a shameless opportunist and people critical of police tactics.

Prince told The Associated Press on Wednesday that one resident told him he was kept away from his house for days, and returned home Tuesday night to find his dogs had eliminated all over the property.

“There is no general blanket allowance for setting the Constitution aside because the Pennsylvania State Police and the FBI are doing an investigation or manhunt,” he said.

Bivens said Wednesday that troopers are “doing their best to balance safety concerns with the needs for residents to be able to travel freely to and from their homes.”

And Ralph Megliola, chairman of the Barrett Township Board of Supervisors, said most residents he’s spoken with believe police are “doing the best job they can” under difficult circumstances.

“Most of them understand,” he said. “They’d rather not be in their houses if there’s a murderer in their backyard.”

Rubinkam reported from northeastern Pennsylvania.