The black Cadillac the suspect drove, with Colorado license plates, matched the description of a car spotted outside Tom Clements' home in Monument, Colo., just before he was fatally shot while answering his front door Tuesday evening.

Evan Spencer Ebel, 28, was gravely wounded in the clash with police Thursday. Authorities said he was not expected to survive and was hooked up to equipment for organ harvesting.

Colorado investigators immediately headed to Texas to determine whether Ebel was linked to Clements' slaying and the killing Sunday of Nathan Leon, a Denver pizza delivery man. Police in Colorado would only say the connection to the Leon case is strong but would not elaborate or say if they believe Ebel killed Clements and Leon.

The Denver Post first reported Ebel's name, and that he was in a white supremacist prison gang called the 211s. A federal law enforcement official confirmed his identity and gang affiliation to The Associated Press. The official was not authorized to speak publicly about the case and spoke to the AP on condition of anonymity.

Ebel is not on the radar of the Southern Poverty Law Center, which tracks extremist groups, but the center rates the gang as one of the most vicious white supremacist groups operating in the nation's prisons, comparable to the Aryan Brotherhood of Texas. Founded in 1995 to protect white prisoners from attacks, it operates only in Colorado and has anywhere from between a couple hundred to 1,000 members, senior fellow Mark Potok said Friday.

The gang has grown into a sophisticated criminal enterprise where members are assigned military titles like "general" and extort money from fellow prisoners, regardless of race. Released members are expected to make money to support those still in prison, Potok said. He said members have to attack someone to get in and can only get out by dying.

"It's blood in and blood out," he said.

In 2005, 32 members were indicted for racketeering and the gang's founder, Benjamin Davis, was sentenced to over 100 years in prison.

The killing of Clements, 58, shocked his quiet neighborhood in Monument, a town of rolling hills north of Colorado Springs, for its brutality: He answered the door of his home Tuesday evening and was gunned down. Authorities wouldn't say if they thought the attack was related to his job, and all Clements' recent public activities and cases were scrutinized.

The Texas car chase started when a sheriff's deputy in Montague County, James Boyd, tried to pull over the Cadillac around 11 a.m. Thursday, authorities there said. They wouldn't say exactly why he was stopped, but called it routine.

The driver opened fire on Boyd, wounding him, Wise County Sheriff David Walker said at an afternoon news conference in Decatur. He then fled south before crashing into a semi as he tried to elude his pursuers.

After the crash, he got out of the vehicle, shooting at deputies and troopers who had joined the chase. He shot at Decatur Police Chief Rex Hoskins four times as the chief tried to set up a roadblock.

"He wasn't planning on being taken alive," Hoskins said.

Boyd, the deputy who was shot, was wearing a bulletproof vest and was at a Fort Worth hospital, authorities said. Officials had said he wasn't seriously injured but later said his condition was unknown.

The car is so far the main link authorities have given between the Colorado case and the Texas shootout. El Paso County, Colo., sheriff's investigators have been looking for a dark, late-model car, possibly a Lincoln or a Cadillac, that a neighbor spotted near Clements' home around the time of the shooting.

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

El Paso County sheriff's officials did not return repeated messages Thursday. In a statement, Lt. Jeff Kramer said investigators will inspect evidence in Texas and would need crime lab analysis before they're able to determine whether the suspect is linked to Clements' shooting.

"These efforts take time," Kramer said.

Other links between Ebel and the Colorado killings aren't clear. Legal records show he was convicted of several crimes in Colorado dating back to 2003, including assaulting a prison guard in 2008. He apparently was paroled, but Colorado Department of Corrections spokeswoman Alison Morgan said she could not release information on prisoners because of the ongoing investigation into Clements' death.

Scott Robinson, a criminal defense attorney and media legal analyst, represented Ebel in 2003 and 2004. He said Ebel had been sentenced to a halfway house for a robbery charge in 2003 before he was accused in two additional robbery cases the following year that garnered prison sentences of three and eight years.

"I thought he was a young man who was redeemable, otherwise I wouldn't have taken the case," Robinson said, saying he didn't recall the details of the case.

Robinson said he knew Ebel before he got in trouble. He said Ebel was raised by a single father and had a younger sister who died in a car accident years ago.

Vicky Bankey said Ebel was in his teens when she lived across from him in suburban Denver until his father moved a couple of years ago. She remembers seeing Ebel once jump off the roof of his house. "He was a handful. I'd see him do some pretty crazy things," she said.

"He had a hair-trigger temper as a kid. But his dad was so nice," Bankey said.

Ebel's father didn't return an after-hours phone message left at his business.

Clements came to Colorado in 2011 after working three decades in the Missouri prison system. Missouri Department of Corrections spokeswoman Mandi Steele said Thursday the department was ready to help in the probe if asked.

"Tom regularly commented that corrections is inherently a dangerous business, and that's all that I'll say," Morgan, who worked closely with Clements, said earlier.

Officials in positions like Clements' get a deluge of threats, according to people who monitor their safety. But it can be hard sorting out which ones could lead to violence. A U.S. Department of Justice study found that federal prosecutors and judges received 5,250 threats between 2003 and 2008, but there were only three attacks during that time period.

The last public official killed in Colorado in the past 10 years was Sean May, a prosecutor in suburban Denver. An assailant killed May as he arrived home from work. Investigators examined May's court cases, but the case remains unsolved.

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Banda reported from Denver. Contributing to this report were Associated Press writers Nicholas Riccardi, Colleen Slevin and Ivan Moreno in Denver, and Jordan Shapiro in Jefferson City, Mo.