The death certificate for Andre Thomas will say he died of agitated delirium from acute cocaine intoxication, the cause of death determined in a lengthy investigation and autopsy by Allegheny County Medical Examiner Dr. Karl Williams.

But for Mr. Thomas' family members and observers of the case, Dr. Williams' explanation -- saying that the use of Tasers by Swissvale police did not factor into the Aug. 5 death -- was insufficient.

"We heard a lot of big talk and didn't get answers," said Mr. Thomas' cousin, Lee Davis, who attended Dr. Williams' news conference yesterday.

"We're going to keep pushing for the truth."

Dr. Williams revealed that Mr. Thomas, 37, had cocaine in his system, but not enough to overdose. In fact, cocaine levels were consistent with casual use of the drug, Dr. Williams said, though he noted cocaine use at various levels can result in death.

In Dr. Williams' analysis, the cocaine caused Mr. Thomas to enter a state of agitated delirium, causing "agitated, aggressive behavior, hallucinations and paranoia."

The evening of Aug. 4, Mr. Thomas was excited and erratic. He knocked on several doors on Hawthorne Street in Swissvale, saying people were trying to kill him and causing some residents who feared for his safety to call 911.

When police arrived, Mr. Thomas was ordered to the ground by Officer Debra Indovina, who stunned him three times with her Taser to subdue him.

An ambulance was eventually called, and Mr. Thomas was taken to UPMC Braddock, where he died at 12:46 a.m. Aug. 5.

Allegheny County District Attorney Stephen A. Zappala Jr., in a news conference later that week, raised the prospect of the death being caused by "excited delirium."

Dr. Williams said brain tissue analysis revealed that Mr. Thomas' death was not a result of the excited delirium syndrome, which advocacy groups contend is a bogus diagnosis but Dr. Williams defended yesterday. Instead, this was a slightly different state of delirium brought on by cocaine use, Dr. Williams said, eventually resulting in cardiac arrest.

Excited and agitated delirium cases are usually caused by cocaine or methamphetamines and result in a flood of chemicals -- from dopamine to adrenaline -- overloading the heart and causing death, said Dr. Paul Paris, director of emergency medicine at the University of Pittsburgh School of Medicine.

Howard Messer, the attorney for Mr. Thomas' family, wasn't buying it, saying the diagnosis appeared to be manufactured.

"They've completely backed away from the idea that it was an excited delirium case and have created this new [agitated] delirium scenario," Mr. Messer said. "Nice try, but no cigar."

The Thomas family hired former Allegheny County Coroner Dr. Cyril H. Wecht to perform a second autopsy, and Mr. Messer said the county has been dragging its feet in getting him autopsy materials.

Mr. Messer said he was arranging to obtain blood, tissue and urine samples -- among other materials -- tomorrow so Dr. Wecht could finish his autopsy. Then the family will decide whether to sue the Swissvale police.

Some witnesses claimed Mr. Thomas was beaten by police at the scene, and Mr. Messer said Dr. Wecht's initial autopsy findings showed evidence of a beating. But Dr. Williams said there was no evidence of head or neck trauma and bruising was minimal.

And, when it came to the most controversial element of police restraint, Dr. Williams claimed there was "no scientific evidence that the Taser had anything to do with it."

But questions remained about Dr. Williams' conclusion that the moderate amount of cocaine turned lethal inside Mr. Thomas' body.

"Why, in Andre's case, he experienced that?" the medical examiner said. "We don't know."