YAKIMA, Wash. -- A Yakima woman faces 15 to 21 years in prison after pleading guilty Wednesday to second-degree murder in the shooting death of her longtime companion.

Tracy L. Johnson, 47, entered the plea in Yakima County Superior Court.

She was arrested in October 2007 and accused of fatally shooting 39-year-old Kelly Walsh.

Prosecutors are expected to recommend a 20-year sentence, including five years for the use of a firearm.

Detectives found Walsh's body wrapped in a tarp in the trunk of her vintage Pontiac Bonneville, parked in the couple's driveway at
619 S. 21st Ave.

Investigators estimated that Walsh, who suffered multiple gunshot wounds, had been dead for several weeks.

Inside the house, police found a .25-caliber gun and a spent shell casing, as well as a notebook that reportedly belonged to Johnson.

In the notebook, Johnson wrote that she loved Walsh but hated Walsh's father, according to a police affidavit. She blamed him for "making her violent." The notebook also stated that she wanted to "make Kelly comfortable for all time."

Police began working on the case after Walsh's mother reported her missing.

Neighbors said Johnson and Walsh had been together for more than
10 years.