A Longview man in prison for assault was sentenced last week to an additional roughly 24 years after pleading guilty and admitting to killing his cellmate, a convicted child sex abuser who had raped the man’s juvenile sister.

Shane Goldsby, 26, previously of Longview, pleaded guilty to second-degree murder without premeditation for killing Robert Munger, 70, of Kelso, at the Airway Heights Correctional Center near Spokane in June 2020.

A 2020 investigation of the murder by the Washington State Patrol states Goldsby struck Munger from behind in a communal prison area hours after meeting him. Goldsby punched Munger in the head about 14 times and kicked his head repeatedly until correction staff intervened within seconds, states the report. Munger died three days later at the hospital.

The Washington State Patrol reported Goldsby wrote a note after Munger’s death stating he did not know of Munger’s crimes until they were housed together.

Questions arose about how the two were put in the same cell, but the Washington State Patrol concluded “there is no evidence suggesting screening staff should have known about the conflict between Goldsby and Munger.”

Munger was found guilty of six felonies — including first-degree rape of a child and three counts of first-degree child molestation — in 2019 in Cowlitz County Superior Court. Cowlitz County Prosecuting Attorney Ryan Jurvakainen previously told The Daily News Munger’s charges involved several victims.

Munger was serving a minimum 43-year sentence when Goldsby attacked him. In 2017, Goldsby was found guilty of second-degree assault with a deadly weapon and was serving about seven years in prison for that crime.