MONUMENT, Colo. — In the weeks before Colorado's top prisons official was fatally shot after answering his front door, he carried out a variety of functions including requesting execution chemicals and speaking to legislators about security issues.

It's unknown what role Tom Clements' position as executive director of the Colorado Department of Corrections might have played in the shooting Tuesday, but investigators said they aren't ruling out any possible motives, including whether it was random or a work-related attack.

Colorado corrections spokeswoman Adrienne Jacobson would not comment on whether Clements had security at his home. Security was stepped up for other state officials, including Gov. John Hickenlooper, who was ashen-faced as he addressed reporters at the Capitol before signing bills placing new restrictions on firearms.