The head of Colorado's prison system was shot dead at his home in what police said may have been a targeted killing.
This was just hours before the governor signed new gun control laws spurred by a rash of deadly mass shootings in Colorado and elsewhere.
Police said Tom Clements, 58, appointed two years ago as executive director of the Colorado Department of Corrections, was shot last night at his home in a secluded wooded area near the picturesque town of Monument, 72 km south of Denver.
The killing did not appear to be linked to any break-in or robbery attempt, said El Paso County Sheriff's Department Lieutenant Jeff Kramer.
He said the shooting did not appear to be random.
"We are sensitive to the high-profile position in which Mr. Clements served and the fact there could be people who would target him based on his position," Kramer said in a statement.
Clements also spent 31 years in the Missouri Department of Corrections, where he became the No. 2 official.
His home sits on a street that is "not a major thoroughfare," Kramer said.
"There's no reason to turn off onto that road unless you had business there."
Kramer said that according to a 911 emergency call for help, Clements was shot after answering the doorbell.
He was found dead by sheriff's deputies arriving on the scene.
Officials began a search for Clements' assailant on Wednesday night but as of yesterday no suspects had been pinpointed, Kramer said.
He said police were investigating a neighbor's sighting of what was described as an unoccupied, "boxy" two-door vehicle idling near the house about 15 minutes before the first 911 call.
The same car was reported seen a short time later traveling away from the scene with a lone, unidentified occupant, he said.
Governor signs gun laws
At a news conference, Governor John Hickenlooper, visibly shaken by news of the shooting, praised Clements as a "great friend to me" and a dedicated administrator.
At a previously scheduled event later, Hickenlooper signed legislation to extend background checks on gun buyers to private firearms sales.
The prospective buyers would pay for the checks.
He also signed legislation limiting the size of ammunition magazines that may be sold in the state.
The measures were introduced in the Democratic-controlled state legislature earlier this year and swiftly passed, moving Colorado to the forefront of a national debate over gun violence, which was re-ignited by several mass shootings in 2012.
They included massacres of school children in Newtown, Connecticut, and moviegoers in suburban Denver.
A previous loophole in state law that exempted firearms sales at gun shows from background checks was closed after the 1999 Columbine High School massacre in Colorado where two students shot dead a teacher and 12 students before committing suicide.
Columbine had stood as the deadliest US public school shooting on record until 20 first-graders and six adults were slain by a gunman last December at the Sandy Hook Elementary School in Newtown.
Five months before the Sandy Hook massacre, a gunman opened fire during the midnight screening of the Batman movie The Dark Knight Rises in the Denver suburb of Aurora, killing 12 people and wounding 58 others.
Hickenlooper, a Democrat, was joined at the bill-signing by sponsors of the measures and relatives of victims of gun violence.
One of them, Sandy Phillips, whose daughter, Jessica Ghawi was killed in Aurora, told the governor, "You've given us a real gift today, adding, "Thank you so much. You're leading the entire country."
A national assault weapons ban backed by President Barack Obama ran into trouble yesterday when US Senate Majority Leader Harry Reid acknowledged there was not enough support for it.