Lisa Clements, the wife of the slain Colorado prison chief, talks to Anderson Cooper on AC360, tonight at 8 p.m. ET.
(CNN) -- Colorado authorities are questioning two associates of the man suspected in the killing of the state prisons director, a law enforcement source close to the investigation said Thursday.
The two men, whom the source declined to identify, are in addition to James Lohr, 47, and Thomas Guolee, 31, two men the El Paso County Sheriff's Office asked police to be on the lookout for on Wednesday. One or both could be headed toward Nevada, the office said.
Police want to question Lohr and Guolee -- whom police described as associates of the white supremacist 211 Crew gang -- in relation to the death of state prisons chief Tom Clements. The man suspected of killing Clements, Evan Ebel, also had been a 211 Crew member. He died in a shootout with Texas deputies.
The other two men, brought in for questioning in recent days by El Paso County authorities, are also 211 Crew members, the source said. Both associated with Ebel in the days before Clements' death, the source said, and at least one is a parolee.
Authorities have also served a search warrant related to one of them, the source said. The source declined to say what the warrant named.
Investigators have said they were looking into whether Ebel might have conspired with other inmates to kill Clements.
Clements was widely recognized for cracking down on prison gangs, including the 211 Crew. He was shot at his home by former gang member Evan Ebel, who was out of prison on parole.
Ebel also is suspected in the killing of part-time pizza deliveryman Nathan Leon, who was slain before Clements.
Authorities have speculated Ebel might have killed Leon for his uniform so he could use it as a disguise in the killing of Clements, who was gunned down on March 19 after he opened his front door.
Due to a clerical error, Ebel had been released early on parole, which he later violated.
He had been sentenced to eight years in prison in 2005 for armed robbery. In 2008, he was sentenced to another four years -- to be served consecutively -- for punching a prison guard.
Two days after Clements was killed, Ebel died in northern Texas in a gun battle with authorities that left a sheriff's deputy wounded.
Kramer said Lohr and Guolee may also pose a threat to the safety of officers who encounter them.
Police have little to go on in order to track them.
"We don't have vehicle information," Kramer said. "We don't have a concerted search out looking for them. We don't know their whereabouts." Lohr has multiple misdemeanor warrants for his arrest unrelated to the Clements case.
Guolee has a felony warrant for his arrest, also unrelated to the Clements case.
Kramer declined to say whether the pair knew Ebel.
CNN's Cristy Lenz contributed to this report.