Evidence collected from a roadside gun battle between a white supremacist ex-convict and Texas police has provided "a very strong lead" for investigators looking into the shooting death of Colorado's prisons chief, a police spokesman said on Saturday.
Evan Spencer Ebel, a 28-year-old parolee from Denver, was killed by police on Thursday after a high-speed chase through Decatur, Texas.
He is now considered a suspect in the death of Tom Clements, executive director of the Colorado Department of Corrections, said Lieutenant Jeff Kramer, a spokesman for the El Paso County, Colorado, sheriff's Office.
Clements, 58, was shot dead on Tuesday when he answered the door at his home near the community of Monument, in El Paso County, about 45 miles south of Denver.
Ebel is also a suspect in the killing two days earlier of pizza delivery man Nathan Leon in Denver, police there said.
Shell casings found at Clements' home were the same brand and caliber of the Hornady 9-mm bullets Ebel fired at Texas police, according to the search warrant filed in Texas for police to search Ebel's Cadillac.
A copy of the search warrant was posted online by the Fort Worth Star-Telegram newspaper.
A Domino's pizza deliverer's shirt or jacket and a Domino's pizza carrier were in the car's trunk, according to the search warrant.
"Obviously this is a very strong lead for us from the items of evidence our investigators brought back from Texas, including the shell casings," Kramer said on Saturday.
"We're looking very hard at Mr. Ebel and are waiting for solid confirmation that it's the same gun" used in the Clements shooting, he said.
A statement from the sheriff's office late on Friday said that bullet casings collected at the scene in Texas would be sent to the state crime lab to determine if the same weapon was used to kill Clements.
Results from the ballistics analysis should be ready by early next week, Kramer said.
Ebel was a member of a white supremacist prison gang, the 211 Crew, and had been paroled in the Denver area, a law enforcement official said.
Authorities were also looking for ties between the death of Clements and the January killing of Mark Hasse, a prosecutor in the Kaufman County District Attorney's Office. Kaufman County is east of Dallas.