Authorities are also looking for a dark-colored "boxy" car seen near the house of Tom Clements, 58, when he was shot around 8:30 p.m. Tuesday in Monument, north of Colorado Springs. The vehicle's engine was running and a witness reported seeing one person driving away in the car.
Lt. Jeff Kramer, of the El Paso County Sheriff's Office, said investigators have not ruled anything out, but the shooting could have been related to Clements' job.
"As the director of the Department of Corrections or any similar type position, it could in fact open someone up to be a target of a crime such as this. Although we remain sensitive to that, we also want to make sure that we remain open-minded to other possibilities as well," Kramer said.
Colorado Gov. John Hickenlooper appointed Clements to the post in 2011 after he served for more than three decades in the Missouri Department of Corrections. He replaced Ari Zavaras, a former Denver police chief who led the department under two governors. The department operates 20 adult prisons and a juvenile detainment system.
Hickenlooper was red-eyed and somber and spoke haltingly Wednesday morning at a news conference in which he said he doesn't think the killing was part of any larger attack against his cabinet, members of which stood behind him, several of them crying. Others dabbed their eyes.
"Corrections is a very different job. You make difficult decisions every time that affect different people," Hickenlooper said, calling Clements dedicated, funny, caring and an expert on the latest and best methods in his field who chose the Colorado job over retirement.
"Tom Clements dedicated his life to being a public servant, to making our state a better place and he is going to be deeply, deeply missed."
Hickenlooper planned to go to Monument to meet with Clements' family after signing gun-control bills.
A family member called 911 to report the shooting. Search dogs were called in to comb through a wooded area around Clements' home, and authorities were going house to house trying to find out what neighbors heard and saw.
Clements lived in a wooded neighborhood of large, two-story houses on expansive 2-acre lots dotted with evergreen trees in an area known as the Black Forest. Long driveways connect the homes to narrow, winding roads that thread the hills. Clements' home was out of view, behind a barricaded of crime-scene tape in the road.
After Clements was appointed, Hickenlooper praised Clements for his approach to incarceration, saying he relied on proven methods to improve prison safety inside and programs that have been shown to improve successful outcomes after offenders are released from prison.
While Clements generally kept a low profile, his killing comes a week after he denied a Saudi national prisoner's request to be sent to his home country to serve out his sentence. Homaidan al-Turki was convicted of sexually assaulting a housekeeper and keeping her as a virtual slave. Clements said state law requires sex offenders to undergo treatment while in prison and that al-Turki had declined to participate.
Hickenlooper ordered flags lowered to half-staff at public buildings until the day after Clements' funeral. Arrangements are pending.
Clements is survived by his wife, Lisa, and two daughters, Rachel and Sara.
Clements received a bachelor's degree in sociology and a master's degree in public administration from the University of Missouri. He started with the Missouri Department of Corrections in 1979 and over his 31 years there worked in prisons as well as probation and parole services. He was director of adult institutions when he left.
Missouri leaders also mourned his death.
George Lombardi, director of Missouri's Department of Corrections, said Clements was "just a very good, decent person."
Missouri Gov. Jay Nixon said in an emailed statement that Clements "dedicated his professional life and his considerable skills to public service and protection, and the citizens of Missouri join the people of Colorado in mourning this tremendous loss."
Associated Press writers Steven K. Paulson in Denver and Maria Sudekum in Kansas City, Mo., contributed to this report.