A high-speed chase ensued, ending about 30 miles away in Decatur, Texas, with Ebel firing out of his window at police, law enforcement said.
"I would say he was running about 100 mph, and he had his left arm out the window and he was just shooting," said Decatur Police Chief Rex Hoskins, whose patrol car was parked in the median as the Cadillac raced past.
The chase ended when the Cadillac screeched onto another road and slammed into an 18-wheel truck, authorities said. With the front of his car crushed, Ebel got out and started shooting again.
Ebel didn't hit any officers this time, they said. But they shot him.
He was taken to an area hospital where he was pronounced dead Thursday night, authorities said.
A prison conspiracy?
Since Tuesday, investigators looking into Clements' killing have told reporters they are considering numerous angles.
One is that Ebel, a former member of the 211s -- a white-supremacist prison gang -- might have conspired with other inmates to kill Clements, Paula Presley of the El Paso County, Colorado, sheriff's department said.
The Department of Corrections told investigators that Ebel was a prison gang member, she said on CNN on Friday.
Clements earned widespread recognition for not only prison reforms but for a crackdown on prison gangs, including the 211s.
Citing media coverage of the shooting and its possible connection with the the 211s, authorities locked down Colorado's prisons on Friday, said state Department of Corrections spokeswoman Alison Morgan.
"We are on full lockdown over the weekend, no visitation or volunteer programs," she said.
Suspect's troubled past
As authorities look for possible links in the case, a troubling portrait began to emerge of Ebel.
By all accounts, Ebel came from a privileged upbringing. His father, Jack Ebel, an attorney and former oil executive, counts Colorado Gov. John Hickenlooper among his friends.
"When I first came out to Colorado 30 years ago, he and I worked in the same oil company," Hickenlooper told reporters Friday.
The governor described Jack Ebel as "generous to a fault," but said the son "had a bad streak."
"We knew his son growing up that he just had a bad streak," Hickenlooper told CNN affiliate KUSA. "I think Jack, his wife, they did everything they could."
Hickenlooper, who did not go into details about the behavior, said he first learned the younger Ebel was a suspect in the killing of Clements on Thursday.
His first reaction? "There can't be two Evan Ebels."