Spencer Johnson, who had a previous domestic violence arrest, pleaded guilty this week to shooting and killing his girlfriend Cory Lumber in July 2016

A Portland man pleaded guilty to shooting and killing his girlfriend following an argument in July 2016.

Police say Spencer Johnson and his girlfriend of 3 months, Cory J. Lumber, got into an argument on the night of July 1, 2016. The fight escalated, and Johnson shot and killed Lumber.

Police found her body the next morning. They also found six firearms inside Johnson's house.

Johnson had a previous arrest in October 2015 for domestic violence.