Knoxville (WVLT) - Knoxville Police have begun a probe into the death of a carjacking suspect in East Knoxville Tuesday night.

That man died after an officer shot him with his Taser.

But police now say the preliminary autopsy shows the Taser shot isn't what killed him.

Volunteer TV’s Gordon Boyd investigates the suspect, the circumstances, and an investigation that now branches in several directions.

Kevin Dwayne Hill is far from the first person to die after being shot from a Taser.

But police now say the medical evidence suggests he died from an unrelated medical condition, and that he had an illegal substance in his system.

These revelations come after Internal Affairs began investigating how and why the Taser was used, an investigation that continues regardless.

Fifty-thousand volts of designed to be non-deadly force.

“Very beneficial to our officers, not only to the suspects we're trying to take into custody, but for the safety of our officers as well,” Spokesman Darryl DeBusk says a Knoxville officer was considering his own safety, the suspects, and fellow citizens when he tazed 39-year-old Kevin Dwayne Hill after confronting him the intersection of Cherry and Magnolia. “The officer repeatedly asked him to put his hands behind his back, he continued to struggle with the officers.”

Police say they'd suspected Hill had tried to carjack a woman nearby.

His criminal convictions date back 15 years–cocaine dealing, weapons possession—evading arrest. urning to assault, resisting arrest, shoplifting—resisting arrest—criminal impersonation, and fleeing and evading arrest twice more—in the last ten years.

Still, “They didn't know who he was when they made contact with him,” DeBusk says.

Nor apparently, did they know he'd been back on the streets only four days when the came face to face with him last night.

“The different callers indicated, one thought he was on drugs,” DeBusk explains. “Just because he died does not mean it was the Taser’s fault. That's something we definitely want to stress.”

DeBusk says all Knoxville officers have undergone extensive training, especially after tasers became standard issue two years ago.

Of 14,000 arrests last year, the Taser came out fewer than 100 times.

“They're looking at policy and procedures to make sure everything was followed correctly by the officers,” DeBusk says.

The full autopsy on Kevin Hill could be back thursday.

The officer who tazed him, and his sergeant supervisor, are on paid administrative leave while Internal Affairs investigates.

But a department spokesman indicates the preliminary autopsy appears to clear the officers of any questions.

Two pieces of technology could settle any doubts.

Video from the officers cruiser camera and the smart chip from the Taser itself, it's like a black box, recording not only how many times the officer fired it, but the length of the blast.