(KTRS) – The 18-year-old suspect accused of killing a St. Louis County Police officer is now charged with murder.

Prosecutor Bob McCulloch announced first-degree murder charges against Trenton Forster Thursday afternoon. Officer Blake Snyder and his partner were called to a south county home just after 5 a.m. by homeowners who said Forster would not leave the home. He had a realationship with a girl in the home.

When officer Snyder arrived, he approached Forster and that is when investigators say he shot the officer. Snyder’s partner then shot Forster five times–he is in critical condition.

The BackStoppers are helping Snyder’s family and any donations should be directed to the organization.