A Casper woman admitted in court Friday to shooting her boyfriend in the trailer they shared near Natrona County High School.

Dawn Marie Rock, 34, pleaded guilty to second-degree murder as part of a plea agreement that comes less than a month before she was scheduled to stand trial for the March killing of Kenneth Walkinshaw.

During a brief hearing in Natrona County District Court, Rock told Judge Thomas Sullins she shot Walkinshaw four times with a .38-caliber revolver.

Before accepting her plea, Sullins asked Rock if she argued with Walkinshaw on the day of the shooting, and whether that resulted in the killing. Rock, shackled and wearing a blue jail uniform, answered yes to both questions.

Rock was initially charged with first-degree, premeditated murder, which would have meant a life sentence if she were convicted. The agreement allowed her to plead guilty to second-degree murder, which carries a sentence of 20 years to life.

Prosecutors also agreed to ask for a sentence of no more than 40 to 45 years in prison, said Assistant District Attorney Dan Itzen. Rock's attorneys will be allowed to argue for a lesser sentence.

"We reached an agreement on a charge that we felt very well might occur in a jury trial itself," Natrona County District Attorney Michael Blonigen said after the hearing. "Even though the evidence was sufficient to support the element of premeditation, it is not unusual in cases of this type, particularly domestic-type cases, for the jury to reach a compromise verdict. And so that is something we addressed through the plea agreement."

Rock's attorney, Public Defender Vaughn Neubauer, declined to comment on the case.

Shortly before 8 p.m. on March 25, a distraught woman called 911 and said she shot her husband, police said. Officers found Rock holding a cell phone in front of an Elm Street home. In a travel trailer behind the home, they found Walkinshaw bleeding from gunshot wounds. He was taken to Wyoming Medical Center where he died.

Rock initially described Walkinshaw, 36, as her husband, but they weren't married, police said. Following the killing, she told a detective that she shot Walkinshaw after he complained about how bad his life had become.

However, during Rock's preliminary hearing in April, a police investigator testified that Walkinshaw's friends and co-worker's told police he appeared to be enjoying life.

Testimony during that hearing indicated Rock had been aggressive toward Walkinshaw several times in the past and even choked him before. Hours before the shooting, Walkinshaw was physical toward her for the first time, choking her during an argument, according to police testimony.

Both Rock and Walkinshaw had been drinking and arguing on the day of the shooting, police said.

Rock is expected to be sentenced in eight weeks.

Reach Joshua Wolfson at (307) 266-0582 or at josh.wolfson@casperstartribune.net.