Colorado Trooper Eugene Hofacker was shot and a suspect was killed Thursday morning on Interstate 70 at the eastern end of Glenwood Canyon.

Hofacker, 31, was in critical but stable condition, according to Colorado State Patrol Chief Scott Hernandez.

Hofacker, a six-year State Patrol veteran based in Vail, was taken to Valley View Hospital in Glenwood Springs. Hernandez did not comment on Hofacker’s injuries but did say the trooper had been wearing his body armor.

“This has been a very tough day,” Hernandez said at a news conference. “This highlights the job that troopers and all of law enforcement do, pulling up on a vehicle and the dangers that exist.”

Authorities said Hofacker and another trooper, who were riding in the same car on their way to a training session, stopped to assist a motorist pulled over on the side of westbound I-70 at mile marker 129. The shooting happened within five minutes.

According to 7News, the suspect was 40-year-old Thomas Ornelas.

Ornelas had a lengthy, violent criminal record. According to state records, in August 1990 he pleaded guilty to second-degree murder in a Denver case. Details and information about sentencing in that case were not immediately available.

Later, Ornelas was charged with multiple crimes in Montrose County. He was sentenced to unsupervised probation in 2007 after he pleaded guilty to third-degree assault, and in 2010 he was sentenced to probation after pleading guilty to obstructing a peace officer.

Ornelas was out on a $75,000 bond in a case out of Mesa County. In that case, he pleaded not guilty to nine counts, including two counts of attempted second-degree murder.

He was scheduled to go to trial in September.

Garfield County Sheriff Lou Vallario said Hofacker was shot when he approached the driver-side window. The second trooper, who was approaching the car on the passenger side, returned fire and killed the driver, Vallario said.

“Fortunately, there was a second trooper to take care of the suspect before he could do any more harm to the trooper who was already injured,” Vallario said.

He said investigators didn’t yet know how many shots were fired.

The suspect was pronounced dead at the scene.

According to the sheriff’s office, Hofacker “lost a lot of blood.”

The incident occurred about 9:10 a.m. west of the Dotsero exit, according to the sheriff’s office.

Vallario said a number of other troopers on their way to the training exercise were in the area. “Literally, within seconds, if not moments after that,” he said, “they were able to help secure the scene, and they were able to start first aid and administer aid to the wounded trooper.”

The sheriff’s office and other agencies were cooperating in the investigation. Colorado Bureau of Investigation spokeswoman Susan Medina said it has sent agents and a crime-scene response team to the site.

The shooting shut down I-70 for several hours. Colorado Department of Transportation spokeswoman Tracy Truelove said the closures were done to allow emergency vehicles access to the scene of the shooting.

Eastbound lanes were completely reopened at 2 p.m., while westbound lanes reopened about 5:15 p.m. near Wolcott at mile marker 157.

The Vail Daily reported that those stuck in traffic got frustrated. The newspaper reported that one man was suspected of waving a gun at CDOT employees who were doing traffic control. That man and a woman were taken into custody by some of the many officers on the scene, and they were later released.

Kieran Nicholson: 303-954-1822, knicholson@ denverpost.com or twitter.com/kierannicholson