Police cars are parked on I-10 near Phoenix early Friday after one state trooper was killed and other was injured in a shooting.
CNN  — 

A person who was fighting with police along Interstate 10 near Phoenix took an officer’s gun and shot two Arizona state troopers Wednesday night, killing one, authorities said.

Trooper Tyler Edenhofer – an officer who was in training – was killed, and Trooper Dalin Dorris was injured in the shooting in Avondale, just west of the capital, police say.

The shooting happened after troopers were called to I-10 around 10:20 p.m. about a person who was “in and out of the roadway, throwing things at cars,” said Col. Frank Milstead, director of the Arizona Department of Public Safety. Police later said the objects were rocks.

The male suspect struggled with troopers and police officers from the city of Goodyear, Milstead said Thursday morning.

“During the struggle, one of the troopers lost his firearm to the subject. The subject fired at least two rounds,” hitting Dorris and Edenhofer, he said.

“Our thoughts and prayers are with his family. Lives have been shattered and ruined, and we’re all in a little bit of a state of shock this morning,” Milstead said.

Police said the suspect was being treated at a hospital after the struggle. He was identified as Isaac D. King, 20.

He has no criminal history, police said.

King could not be reached for comment, and it was not immediately clear whether he had an attorney.

Eastbound I-10 was closed at the shooting site while police investigated, video from CNN affiliates KTVK and KPHO shows.

Dorris, who was shot in the shoulder, was recovering Thursday in a hospital, Milstead said.

Before police arrived, “some citizens pulled over to the right-hand side to actually get the subject out of the roadway,” Milstead said.

Edenhofer graduated from the state Department of Public Safety’s academy on May 4, Milstead said. Dorris has been with the department since 2005.

CNN’s Chris Boyette contributed to this report.