Authorities hunting a survivalist and suspected cop killer in the rugged woods of eastern Pennsylvania say they believe they are closing in on him and have brought in a 6.5-ton armored tactical vehicle dubbed "The Rook" and outfitted with robotic video cameras to assist in a search now entering its 12th day.

Lt. Col. George Bivens told a press conference Wednesday that officers believe they spotted 31-year-old Eric Frein, who is charged with killing one trooper and wounding another, as recently as Tuesday. However the distance and extremely rugged terrain separating the officers from Frein in each sighting meant "he has had the ability to disappear," Bivens told reporters.

Police found empty packs of Serbian-branded cigarettes and soiled diapers believed to have been left by the suspect, Bivens said, helping to cement authorities' belief they are close to him. Police believe Frein is using diapers so he can remain stationary for long periods of time.

The massive ongoing search now includes a 13,000-pound machine that allows officers to gain entry to the second story of a house without a ladder or to deploy snipers to rooftops.

“The Armored Deployment Platform (ADP) allows officers to approach structures with reduced exposure,” according to manufacturer Ring Power Tactical Solutions. “A team can be placed anywhere and have a secure position from which to make better tactical decisions.”

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The vehicle can also be outfitted with a hydraulic breaching ram, a grapple claw with 4,500 pounds of lifting capacity and a vehicle extraction tool.

“The ram is equipped with four low-light video and one infrared, forward-view cameras recessed into the end — one on each side and one in front — giving the operator a 360-degree view of the breaching area,” a description of the device reads. “The video images are transmitted to the viewing screen inside the cab with the operator. The operator can view single camera feeds full screen, or divide the screen into 6 views to see all ram camera, and all of these can be transmitted to the command center.”

Authorities say Frein ambushed the state police barracks in Blooming Grove on Sept. 12, fatally shooting Cpl. Bryon Dickson and wounding Trooper Alex Douglass. Police believe Frein, a Canadensis resident and self-taught survivalist, has been hiding in the dense woods surrounding his neighborhood.

The search for Frein — now in its 12th full day — has resulted in frequent unannounced and indefinite roadblocks in Canadensis. Some residents have resorted to sleeping in their cars due to entire neighborhoods being cordoned off.

Troopers issued a “shelter-in-place” order last week that kept some residents from leaving their homes for more than a day, while others who weren’t already at home could not return. Residents said the directive left elderly residents unattended and pets unfed, as well as lost wages for workers who couldn’t reach their job sites.

Adam Christmann said he has been barred from his home at least twice since the search began. He said he was frustrated as he waited at a roadblock near his home Monday afternoon.

“We don’t know when we can go home, or you don’t know if you can get out,” Christmann said. “Families are getting separated.”

Another resident, Bill Mew, said the intense manhunt has been nerve-wracking.

“You start thinking to yourself, is this guy standing outside your front door? So you start looking out the windows, and then you think to yourself, that’s not such a good idea, in case he’s looking back,” Mew said.

The Associated Press contributed to this report.