A Chicago doctor committed suicide Saturday in the Allegheny County Jail, where he was being held on charges he caused the death of a Wisconsin motorcyclist in a September crash on the Pennsylvania Turnpike as police chased him at high speeds through two states.

Dr. Shiva Lal Acharya, 33, a Nepalese doctor who resided in Chicago, died after hanging himself at about 11:30 a.m. Saturday, according to Ramesh Lamichhane, the doctor's nephew who lives in Harrisburg and said he received notification from the Allegheny County medical examiner's office.

The medical examiner's office confirmed Dr. Acharya's death but said an autopsy would not be done until today to determine the cause of death. The medical examiner's office referred all requests for information to the Allegheny County Police, who are investigating the death but were unavailable for comment yesterday.

"This was unexpected. I thought he would be safe in jail," said Mr. Lamichhane, who received a phone call from Dr. Acharya just two hours before he committed suicide. "He was talking slowly but there was no indication he was going to do this."

Mr. Lamichhane said his uncle was bipolar and had been having "mental problems for a couple of years." He said his uncle had regular contact with a doctor while in the jail and was receiving medication.

"I told him we had arranged for a private attorney and that because of his condition he would be released soon, maybe in a day or two," Mr. Lamichhane said. "I told him not to worry. Because I was in my car driving he said he would call me back that evening."

Mr. Lamichhane said the circumstances surrounding the hanging, including how his uncle was able to hang himself and with what, were unclear from the medical examiner's phone call. He was told his uncle left a suicide note that said, "Nobody can judge me. I want freedom."

Early on Sept. 4, Dr. Acharya was driving from Chicago to a job interview in Easton, Pa., when he began fleeing Ohio Highway Patrol officers at speeds of up to 120 mph because he did not have a valid driver's license in that state due to a previous drunken driving charge.

The chase of Dr. Acharya's black BMW was continued by Pennsylvania State Police until the doctor lost control of his car 33 miles from the Ohio-Pennsylvania state line in the Warrendale area and slid into a motorcycle operated by Keith Brown, 46, of Green Bay, Wis., who died as a result of the crash.

Following the crash, Dr. Acharya fled the scene, entering woods along the turnpike. After more than four hours, he emerged from the woods two miles east of the crash scene and surrendered to state police.

After a hearing Sept. 26, Dr. Acharya was ordered held without bail on charges of involuntary manslaughter, homicide by vehicle, third degree murder, fleeing and eluding police, causing an accident involving death, failure to notify police of the accident and fleeing the scene of a fatal crash, plus numerous traffic violations.

Dr. Acharya is survived by a wife, from whom he was estranged, and a 5-month-old son. His wife and son live in Nepal.