An Illinois teenager who died after police shot him twice with a stun gun might have been in an agitated mental state where unusual strength is possible, possibly supporting police claims of a wild tussle with the 130-pound boy, a pathologist said Wednesday.

Dr. Phillip Burch, St. Louis' deputy chief medical examiner, said an autopsy Tuesday on 17-year-old Roger Holyfield showed no overt signs of trauma or foul play that might have explained why the boy died.

Holyfield died Sunday, a day after the confrontation with police in Jerseyville, Ill.

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Burch said he's investigating the possibility that Holyfield died from "excited delirium," which he described as a mental state "where someone is out of control and can do physical feats normally considered impossible."

Such feats also could include continued struggle even after being shot with a high-voltage stun gun, he said.

"They pick up heavy objects, can pick up a human being and throw them — things they wouldn't normally be able to do," Burch said, calling such a state in Holyfield's case "definitely a possibility."

Described as an overdose of adrenalin, the heart-racing condition affects mostly young men with histories of drug use or mental illness and what are thought to be brain abnormalities, Vincent DiMaio, a Texas medical examiner and proponent of the diagnosis, told The Associated Press recently.

Holyfield vomited at the scene and was taken by ambulance to a local hospital, then flown to a St. Louis hospital where he died about 23 hours after the confrontation.

Holyfield's family members have not returned messages this week to discuss the teenager's movements or frame of mind before the confrontation.

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