DENVER (AP) ? Texas authorities are investigating whether a black Cadillac that led deputies on a gunfire-filled chase through a rural county on Thursday is linked to the slaying of Colorado's state prison chief.
The car, which has Colorado plates, matches the description of the vehicle seen leaving Tom Clements' house shortly before he was fatally shot Tuesday night while answering his front door.
"There is an investigation into that right now," Montague County Sheriff Paul Cunningham said. "There's nothing confirmed."
The chase began about noon in Montague County, about 100 miles northwest of Dallas, when a deputy stopped the Cadillac, Cunningham said. He said he did not know the reason for the stop.
The car's driver fired on the deputy, then drove off, Cunningham said. The deputy alerted local law enforcement, which found the car heading south on a highway in the town of Decatur.
The Cadillac crashed into a truck, Police Chief Rex Hoskins told the Wise County Messenger in a videotaped interview. The driver opened fire on authorities and was shot, then taken to a Ft. Worth Hospital, officials said.
El Paso County, Colo., sheriff's investigators were looking for a late-model car, possibly a Lincoln or a Cadillac, that a neighbor spotted near Clements' home around the time of the shooting. Lt. Jeff Kramer refused to say what other clues may have been found after Clements' neighborhood was canvassed by officers.
Clements, 58, was killed as he answered the door to his home Tuesday night in Monument, a town of rolling hills and alpine trees north of Colorado Springs. His death stunned law enforcement colleagues in Colorado and Missouri, where he spent most of his career as a highly respected corrections official.
Police haven't said if they think his death was linked to his job.
Denver's KMGH-TV reported Thursday that Clements may have put a bicycle up for sale for $1,200 on Craigslist. Kramer told the station, "I can't speak to the efforts behind this tip, or the level we are giving it."
In recent weeks, Clements had requested chemicals to plan for the execution of a convict on Colorado's death row and denied a Saudi national's request to serve out the remainder of a sentence in his home country. Officials refused to say whether they were looking at those actions as possible motives.
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," said Alison Morgan, a Colorado corrections spokeswoman who worked closely with Clements.
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.
"We were looking for anybody who had a grudge against May," Jackson said.
Steven Swensen, a former U.S. marshal who runs a company that provides security advice for court personnel, said one problem is that if someone really wants to harm a person, they usually don't send a warning.
"The person who makes a threat isn't the most likely to carry out on a threat," he said.
Glenn McGovern, a senior investigator with the Santa Clara County district attorney's office in California, tracks attacks on judges, prosecutors and senior law enforcement officials worldwide. He tabulated 133 such incidents in the U.S. since 1950.
"When I was looking at these attacks, very few gave any kind of threats," he said. "When it comes up, it's out of left field."
Mike McLelland is district attorney in Kaufman County, Texas, where one of his prosecutors was gunned down in January walking to the office through the courthouse parking lot.
McLelland said the attack was a "well-executed assassination" and that investigators have had to comb through every case the lawyer, Mark Hasse, handled. McClelland is still baffled at what might have sparked the slaying.
"Nobody is excluded and everybody is included," he said of investigations like these. "They're knocking over every rock they can."
Associated Press writers Colleen Slevin in Denver and Jordan Shapiro in Jefferson City, Mo., contributed to this report.