DENVER – As Colorado's governor signed a hard-won package of gun control measures on Wednesday, officials across the state were reeling from the shooting death of Colorado's prisons chief.
In the pine-covered hills of the central town of Monument, investigators were searching for traces of the person who walked up to the home of Tom Clements, the executive director of the Department of Corrections; rang the doorbell; and gunned him down as he answered the door about 8:30 Tuesday night.
Officials with the El Paso County sheriff's office said they were looking for a "boxy" two-door car that had been spotted Tuesday night in the neighborhood, its engine running but with nobody inside. There were few other insights about who had shot Mr. Clements, or why.
Investigators said Wednesday morning that they had no suspect, and that they did not believe robbery was a motive. They said Mr. Clements's post, overseeing more than 20,000 inmates in Colorado's prisons and parole system, might have made him a target.
News of the shooting rippled through the State Capitol, where lawmakers and crime victims had gathered to watch Gov. John W. Hickenlooper sign the gun legislation. Staff members asked one another, "Are you O.K.?" Tearful elected officials hugged and shared memories of Mr. Clements, 58, recalling him as a dedicated public servant who had been wooed from retirement to work in Colorado after a career with Missouri's Department of Corrections.
Mr. Hickenlooper's voice cracked as he spoke about Mr. Clements's death and faced the task of publicly grieving after another high-profile shooting. He called it "an act of intimidation" that had cut down a thoughtful and deliberative man who had tried to reform Colorado's prisons by reducing the number of inmates in solitary confinement.
"He did his job quietly and intently," Mr. Hickenlooper said, joined by his cabinet and elected officials. "We are all grieving."
Several people praised Mr. Clements's dedication to corrections officers and inmates alike. He held town hall meetings with prison staff. He tried to address the grievances of working long hours in a sometimes dangerous job. After he was seriously injured in a bicycle accident, Mr. Clements climbed into a wheelchair last September to attend the funeral of a corrections officer who had been fatally stabbed in the neck by an inmate in a prison kitchen.
About a month before his death, he appears to have put his Kona mountain bike up for sale on Craigslist, offering a "lightly ridden" dual suspension mountain bike for $1,200 or an even trade. The ad was signed "Tom," and gave a cellphone number registered to his wife.
Appointed by Mr. Hickenlooper in January 2011, Mr. Clements walked into a department facing budget cuts and a dwindling number of prisoners. He oversaw the closing of two prisons, a difficult process that can reverberate across communities that depend on the associated jobs and state money.
Mr. Hickenlooper said Mr. Clements had been supportive of the gun measures "but not particularly active" during their emotional and contentious path toward passage.
The new laws require background checks for private gun sales in addition to the checks already mandated for purchases at shops and gun shows. They also ban ammunition magazines with more than 15 rounds, a feature that the governor said could turn "killers into killing machines."
"Someone bent on destruction, if they're slowed even for just a number of seconds, that allows someone to escape," he said Wednesday.
As Mr. Hickenlooper signed the bills, he was joined in his office by a handful of people who lost loved ones in shootings at Columbine High School in 1999, at an Aurora movie theater in July and at Sandy Hook Elementary School in Newtown, Conn., in December.
"I started crying," said Tom Mauser, who became a gun control advocate after his son Daniel was killed at Columbine.
Mr. Mauser wore a suit to the Capitol on Wednesday in a nod to the formality of the occasion. But on his feet were Daniel's sneakers.
Dan Frosch contributed reporting from Denver, and Timothy Williams, Alain Delaqueriere and Christine Hauser from New York.nation
This article originally appeared in The New York Times.