in Texas — may also have killed a pizza delivery man and Colorado Corrections Director Tom Clements, who was shot to death at his front door Tuesday night in the Denver suburbs.

Authorities from Colorado were in Texas on Friday, examining the car for evidence that might tie Ebel to the Colorado killings.

In a search warrant (.pdf) seeking permission to search the car Ebel was driving, Texas Rangers told a Wise County judge that Hornady 9mm shell casings were recovered at the scene of the shootout in Decatur, which it said were the same brand and caliber used to kill Clements.

Authorities from both states offered few other details Friday about what evidence they have turned up and stressed that the investigation was still open.

One theory is that the Coloradogunman killed the delivery man for his uniform and used the disguise to get Clements to open the door. Investigators also believe the spree may be connected to a gang of white supremacists who are still in prison.

"We don't know yet exactly whether this is the guy," Colorado Gov. John Hickenlooper told reporters. "There's some indication. I hope it is."

Wise County, Texas, Sheriff David Walker said investigators had "no idea" why Ebel was in Texas. Medical examiners ruled Friday that he died of a single gunshot wound to the middle of the forehead.

Two days later and hundreds of miles away, late Thursday morning in Texas, authorities came across a dark sedan in a traffic stop. The man inside shot a sheriff's deputy three times before speeding away.

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