COLORADO SPRINGS, COLO. -- Colorado Springs Police officers who thought they were investigating a suicide ended up arresting a man for murder Tuesday.

According to officers, 26-year-old Louis Mamo shot and killed his wife Karen at the Fillmore Ridge Apartments on Chestnut Street..

The original call was for a suicide, but after finding the 25-year-old woman dead from an apparent gunshot wound, investigators quickly gathered enough evidence to arrest Mamo for the killing.

Mamo will be charged with second degree murder.

This is the 20th homicide in Colorado Springs in 2012, compared with 25 at this time in 2011.