Authorities investigating the death of Colorado's prisons chief are telling law enforcement officers to be on the lookout for two known associates of a white supremacist prison gang.

El Paso County sheriff's Lt. Jeff Kramer said an officer safety bulletin was sent out Wednesday regarding James Lohr, 47, and Thomas Guolee, 31.

Lohr and Guolee aren't being called suspects in the death of Colorado Department of Corrections chief Tom Clements, but their names have surfaced during the investigation, Kramer said. He wouldn't elaborate.

Kramer said Lohr and Guolee are known associates of the 211 Crew. That's the same gang whose members included Evan Ebel, who is suspected of fatally shooting Clements on March 19 and a pizza deliveryman two days earlier.

Ebel was killed in a shootout with Texas authorities after the deaths.

Investigators have said Ebel is the only suspect in Clements' death but haven't given a motive. But they have said they're looking into his connection to the gang he joined while in prison, and whether that was connected to the attack.

Sheriff's investigators don't know the whereabouts of Lohr and Guolee or if they are together, but Kramer said it's possible one or both of them could be headed to Nevada or Texas.

Both are wanted on warrants unrelated to Clements' death. They are believed to be armed and dangerous.

Clements, born in St. Louis, worked for 31 years in the Missouri Department of Corrections, both in prison and as a parole officer, before he was hired in Colorado.