Former Marine pleads guilty to first-degree murder

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

A former Marine will spend the next 40 years in a Virginia prison after pleading guilty to first-degree murder.

Don Walker was a corporal at Cherry Point in North Carolina when he was arrested for the December 2010 murder of his girlfriend's estranged husband in Montgomery County.

Investigators say Walker broke into 25-year-old Matthew McPeak's Christiansburg home, turned off the power and ambushed him when he came home.

McPeak was stabbed repeatedly with a hunting knife.

McPeak's wife, Danielle received a 40-year sentence in May.