Shell casings collected at the scene of Evan Ebel shootout with authorities in Texas were fired from the same gun used in the shooting death of Tom Clements, the El Paso County Sheriff’s Office said Monday.

Lt. Jeff Kramer said the ballistics analysis matched the casings to a scientific certainty.

“The confirmation goes well beyond acknowledging the same caliber and brand of ammunition being used,” Kramer stated. “It is based on unique and often microscopic markings left on the casings at both scenes.”

Ebel, 28, was fatally wounded in the shootout and is suspected in the killing last Tuesday of Colorado Department of Corrections director Tom Clements at his home near Monument. Clements, 58, was shot in the chest around 8:30 p.m. and witness statements described a late 90’s “boxy” shaped vehicle, dark or black in color, as being at scene shortly before and after the shooting.

On Thursday, Ebel was fatally shot by police in Texas after he shot and injured a deputy and led authorities on a cross-county 100 mph chase that ended in a crash.

Ebel was connected to Clements’ death investigation after Texas officials searched his car and found shell casings identical to the ones recovered from the Monument killing. The Cadillac Ebel was driving also matched witness descriptions from the night of the slaying.

Additionally, Texas Rangers filed a warrant that tied Ebel to the Denver-area shooting of Nathan Leon, a part-time pizza delivery man whose body was found March 17 in Golden.

Sunny Jackson, a spokesman for the Denver Police Department, declined to say whether the department has completed ballistics analysis on their case. He said the department doesn’t discuss evidence as a matter of policy.

“We do believe the case in Texas does have strong ties to our Denver case,” he said.

Since his capture and death in Texas, Ebel’s possible involvement with a violent white supremacist gang known as the 211 Crew and his prison background have come into question, as authorities try to identify a motive for the deaths.

According to Kramer’s statement, investigators are actively pursuing all angles to determine whether Ebel acted alone in the shooting of Tom Clements or if others were involved.