Investigators are looking into whether a paroled white supremacist may have killed a pizza delivery man and gunned down the top prisons official in Colorado before he led Texas authorities on a wild chase and shootout. NBC's Kristen Dahlgren reports.

Shell casings from the same type of ammunition that was used in the slaying of the top prisons official in Colorado were also found near the car of a paroled white supremacist who led Texas police on a wild chase and shootout, authorities said in court records filed Friday.

Investigators are looking into whether the parolee, Evan Spencer Ebel, 28 — who died Thursday after the chase and shootout 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.

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One theory is that the Colorado gunman 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.

As more police followed, the man opened fire again.

"When he came by me, he was running I'd say around 100 miles an hour, just had his left arm out the window, and he was just shooting," Decatur Police Chief Rex Hoskins said. "He wasn't planning on being taken alive."

Authorities say the suspect collided with an 18-wheeler, got out of his car and kept firing until officers shot him. Medical examiners in Tarrant County, Texas, said Ebel died Thursday afternoon.

Inside the suspect's mangled car, authorities found a pizza delivery uniform that police believe may be linked to the murder of Nathan Leon, a Domino's delivery man, Sunday in Golden, Colo.

The car in the crash had a Colorado license plate and matched at least the vague description of the car that was seen outside Clements' home.

The deputy who made the traffic stop, Montague County, Texas, sheriff's Deputy James Boyd, was wearing a bulletproof vest and was taken to a hospital in Fort Worth. He was recovering Friday.

Sources told NBC station KUSA of Denver that Ebel had been recruited into a white supremacist gang called the 211 Crew.

Mark Potok, a senior fellow at the Southern Poverty Law Center, which tracks hate groups, said the gang was extremely vicious. He said it requires its members who leave prison to make money through criminal enterprises and return it to gang leaders.

He said the gang has a "blood in, blood out" ideology, meaning its members must carry out a violent attack to get in and can't get out until they themselves die.

The gang was implicated in the 1997 killing of an African immigrant at a Denver bus stop. One of its members, Nathan Thill, pleaded guilty to murder and said at his sentencing that the immigrant was wearing an "enemy uniform," which Potok said was understood to mean black skin.

The gang is believed to have several hundred to 1,000 members, most of them in Colorado prisons. It gets its name from a section of the California penal code that deals with robbery. Potok said it wasn't clear why the gang was named for that section.

"The bulk of it is still inside the prisons, but increasingly they're spilling out onto the streets," he said. "A lot of drug-running, weapons trafficking, other crimes. They're well-known for the harshness of the discipline on members — disobey a rule and you're risking your life or a serious beating."

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