ST. AUGUSTINE, Fla. -- A man who died after being subdued by sheriff's deputies with a stun gun died of cardiac arrest, according to a medical examiner's report.

St. Johns County Sheriff Neil Perry said the autopsy showed no drugs in the system of Lewis King (pictured, left), 39, who died while being transported to a hospital Dec. 9.

Deputies had stopped King's sport utility vehicle for a broken tail light. When they began questioning King about a suspicious container inside the vehicle -- which they suspected may have contained drugs -- King sped off with a deputy hanging onto the car.

STATEMENT FROM MEDICAL EXAMINER TERRENCE STEINER The Office of the Medical Examiner, District 23, has determined that the cause of death of Lewis King was due to cardiac arrest due to hypertrophic and ischemic cardiomyopathy. This individual suffered severe hypertrophic cardiomopathy (massive enlargement of the heart) of unknown cause. This was complicated by significant arteriosclerotic thickening of coronary arteries. All toxicology testing was negative. As the arrest occurred, following stress and physical exertion during law enforcement apprehension, including attempted Taser control and restraint, the manner of death was deemed "Accident."

King then drove into a wooded area and left his car. He was subdued a few minutes later by deputies, one of whom fired two 5-second bursts from his Taser gun when King refused to comply with instructions.

"(The medical examiner) believed, based on the evidence from the autopsy, that Mr. King got excited, his heart was in bad shape, and he had a heart attack from that excitement," Perry told Channel 4. "Obviously he did get excited .... He was in an agitated, excited condition when the deputies approached him."

Linnes Finney Jr., the King family attorney, said they knew all along that there would be no drugs found in King's system.

"We took the position all along that was poppycock," Finney said. "It's difficult to see it as accidental death when he was Tasered and in an altercation."

Perry denied the claim that the stun gun could have killed King.

"The Taser didn't have anything to do with it. This guy was Tased, but he didn't die for a pretty good while. He died of a heart attack, and the medical examiner clearly says that here," Perry said.

An outcry of the West Augustine community claiming race played a part in his arrest and death has prompted the U.S. Department of Justice's Civil Rights Division in Washington, D.C. and the U.S. Attorney's Office to conduct an investigation alongside the FBI.