Nathan Spiess was identified Wednesday as the officer whose leg was amputated following a chase on Interstate 70. He was resting after a successful surgery the day before, police said.

St. Louis police are releasing the name of a police officer critically injured in the line of duty earlier this week. According to Mitch McCoy, a St. Louis Metropolitan Police Department spokesman, Officer Nathan Spiess was struck by a vehicle on Interstate 70 while attempting to arrest a suspected car thief.