An officer encounters a shirtless man raving in the streets and rolling on the ground.

"Oh … officer, please help me … this guy beat me up," the man says through short breath.

"How much you smoke, man?" the officer responds.

"I don't do nothing," the man replies shortly before running out into traffic. The officer takes him down and handcuffs him. It takes five officers to restrain the hysterical individual. Stepping back from the prisoner, officers take a second to catch their breath and then realize the man has lost consciousness and he's not breathing. Officers perform CPR in a frantic effort to revive him. But even medical crews can't revive the man. In all, the event lasts just 12 minutes.

Video of this ordeal is posted on www.exciteddelirium.org at the University of Miami.

An expert in the condition known as "excited delirium" says neither police, Tasers nor anti-depressants are the cause of people suddenly dying in police custody. Rather, it is a rare brain disorder that can be triggered by either drugs or mental illness and is often fatal no matter what police do.

The issue of excited delirium has become a topic in the recent tragic death of Brian Cardall, who died earlier this month after being Tasered twice by Hurricane police. In fact, in recently released police recordings of the incident, officers are overheard saying:

"Excited delirium, huh?"

"Yeah."

In the tapes, Anna Cardall describes her husband "freaking out" and taking off all his clothes and running into traffic.

Dr. Deborah Mash, professor of neurology and molecular and cellular pharmacology at the University of Miami, says she has studied 90 cases of excited delirium for over 20 years. However, Mash's research remains controversial and some human rights groups call excited delirium simply a convenient term that excuses police brutality.

The American Medical Association does not recognize it as a medical condition, nor does the International Association of Chiefs of Police. It is also not listed in the chief psychiatric reference book.

But Mash maintains that years of research shows there is a rare genetic condition which lies dormant in a few people and can be triggered by drugs such as cocaine, crack or methamphetamine. The result is a severe psychotic episode. The person's body temperature skyrockets to 106 degrees or higher and the connection between the heart and brain is disrupted, leading to sudden death.

"These people are on a lethal path," Mash said. "They're in a state of exhaustive mania."