(CBS) MONUMENT, Colo. - Authorities are searching for a car seen near the house of Tom Clements, the executive director of the Colorado Department of Corrections, at the time of his murder in Monument, Colo., on Tuesday night, CBS Denver reports.
Police said Clements was shot and killed after he opened the front door of his house at approximately 8:30 p.m. A family member in the home called 911 and apparently didn't see the shooter.
A suspect had not been apprehended as of Wednesday morning, but officials said they had a vehicle of interest in the case. A dark-colored "boxy" car was seen near the house, the vehicle's engine was running and a witness reported seeing one person driving away in the car.
At a news conference Wednesday morning, authorities said investigators have not ruled anything out, but the shooting could be related to Clements' job.
"We're sensitive to the fact that serving in that type of position could in fact make him a target or folks would have motive to target him in a crime such as this however we're making sure we remain open minded to a number of other theories as well," El Paso County Sheriff's spokesman Lt. Jeff Kramer said.
Clements, 58, was appointed to serve as the head of the DOC by Governor John Hickenlooper in January 2011 after he served for more than three decades in the Missouri Department of Corrections. He oversaw operations of state and private prisons and parole operations.
Hickenlooper, red-eyed and somber at Wednesday's news conference, said he doesn't think the killing was part of any larger attack against his cabinet.
In an email to Department of Corrections employees notifying them of the killing, Gov. Hickenlooper said, "I can hardly believe it, let alone write words to describe it. I am so sad. I have never worked with a better person than Tom, and I can't imagine our team without him."
The governor described Clements as "unfailingly kind and thoughtful."
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.
Al-Turki, a well-known member of Denver's Muslim community, was convicted in state court in 2006 of unlawful sexual contact by use of force, theft and extortion and sentenced to 28 years to life in prison. A judge reduced the sentence to eight years to life.
Al-Turki insisted the case was politically motivated. He owned a company that some years ago sold CDs of sermons recorded by Anwar al-Awlaki, killed in a drone strike in Yemen in 2011.
Al-Turki's conviction angered Saudi officials and prompted the U.S. State Department to send Colorado Attorney General John Suthers to Saudi Arabia to meet with King Abdullah, Crown Prince Sultan and al-Turki's family.
After Clements' shooting, someone with the State Department called the Colorado Corrections Department.
Prisons spokeswoman Alison Morgan said she had no details on the call other than to say it wasn't connected to the shooting investigation and may have been a simple courtesy. "They called us because we have a cooperative international program with them," she said.
State officials said they have increased security for top Colorado government appointed officials and have increased security at the governor's mansion in the wake of the incident. Officials told CBS Denver the move was purely precautionary and there was no threat that would make it seem other state leaders were in danger.
Hickenlooper ordered that all flags lowered to half-staff Wednesday on all public buildings statewide in memory of Clements.
Clements is survived by his wife, Lisa, and their two daughters.
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