Updated

State police dispatcher Nicole Palmer had just arrived for her 11 p.m. shift and was on the phone with a man complaining about his neighbor's fireworks when she heard a gunshot.

An assassin's bullet had slammed into the chest of her co-worker, Cpl. Bryon Dickson II, who was just leaving for the night. He immediately crumpled to the ground, just outside the front doors of the Blooming Grove barracks in northeastern Pennsylvania.

Palmer — the first witness in the trial of Eric Frein, who is charged in the 2014 ambush — said she opened the door and found Dickson on his back, looking up at the night sky and mouthing "help me."

He died a short time later.

Palmer's dramatic testimony Tuesday captured a portion of the horror and chaos that unfolded at the barracks on Sept. 12, 2014, when a sniper opened fire from a densely wooded area across the street, striking Dickson and a second trooper, Alex Douglass.

Frein, 33, an anti-government survivalist and expert marksman, eluded capture for nearly seven weeks before U.S. Marshals found him at an abandoned airplane hangar.

Prosecutors are seeking the death penalty. Testimony resumes Wednesday.

As the trial opened, Pike County First Assistant District Attorney Bruce DeSarro asked jurors to deliver "full justice" to Frein, calling him an assassin who targeted law enforcement in hopes of sparking a revolution.

Frein "slithered through the underbrush," concealed himself in the trees and took aim.

"Right then and right there, Cpl. Dickson's service and his watch on behalf of all of us came to an end," DeSarro said.

Palmer, the trial's first witness, told the jury that after Dickson asked her for help, she ran back inside to try to alert others in the barracks, then returned to ask him what had happened.

"I've been shot. Drag me inside," he managed to say, Palmer testified.

"I looked at him and told him, 'I can't,'" she recounted tearfully.

Prosecutors showed surveillance video of the shooting, which showed Dickson falling to the ground, followed by Douglass, who had knelt beside his mortally wounded comrade. Douglass then crawled into the lobby on his stomach — his legs immobilized by the gunfire — where a trooper dragged him through a doorway and out of sight.

Other troopers drove a patrol SUV into the parking lot and used it as a shield so they could drag Dickson into the barracks and begin attempts to save his life.

Frein's own attorney acknowledged the enormity of the crime.

"It's a tragedy I don't know how this county will recover from," Michael Weinstein told jurors in a six-minute opening statement.

DeSarro showed jurors the crumpled notebook pages that police found during the manhunt — part of a journal written in Frein's hand in which the gunman describes how he "got a shot around 11 p.m. and took it," watching one of his victims fall "still and quiet."

He also showed them portions of a letter that authorities say Frein wrote to his parents while on the run. In it, Frein spoke of revolution and said "the time seems right for a spark to ignite a fire in the hearts of men."