Spokane County Medical Examiner Sally Aiken ruled Otto Zehm’s death to be a homicide. The technical cause was “hypoxic encephalopathy due to cardio pulmonary arrest while restrained in a prone position for excited delirium.”

Medical examiners are increasingly invoking “excited delirium,” but what is it? And does hogtying people and leaving them on their stomachs exacerbate it? What about the effects of stun guns?

Good luck finding clear-cut answers to those questions. Aiken refers to the research on the effects of restraints as “conflicting and somewhat controversial,” according to the city attorney’s office.

Human rights groups, such as Amnesty International, claim that many in-custody deaths can be blamed on stun guns such as the Tasers used by the Spokane Police Department. Stun gun manufacturers and police departments rebut that claim by noting that many of those deaths are attributable to victims being in a state of excited delirium. In fact, they say that in some cases the victims would have died even without police involvement.

So who is right?

The answer is important because it could lead to an entirely different approach for police officers once they conclude that they are dealing with someone who displays the symptoms of excited delirium. In general that means a person who is extremely agitated, unresponsive to commands, impervious to pain and demonstrates superhuman strength. Police reports indicate that Zehm showed many of these symptoms.

Complicating matters is that police departments could be held liable for in-custody deaths if it’s determined that the actions of officers either triggered or exacerbated a delirium-related death or that departments failed to properly educate their officers on how to react. The specter of lawsuits has a way of driving information – and the truth – underground.

Spokane is not the only city dealing with this problem. It’s become a national issue, which is why the U.S. Department of Justice announced in June that it was going to review up to 180 cases of people who have died after being subdued by stun guns. Other possible factors will also be reviewed, such as age, weight, drug use and, yes, excited delirium. It isn’t clear whether hogtying and other methods of restraining people will be a part of the study.

The University of Toronto researched cases of people who died after being restrained for excited delirium and found strong evidence that either leaving them in a prone position or applying pressure to the neck were contributing factors. Just like Zehm, each victim in the study lapsed into a state of calm before they stopped breathing. The study was conducted in 1998 and obviously has not been universally accepted considering that police departments continue their restraint practices.

Medical examiners will play a role in the Department of Justice review. We hope the result will be a better understanding of in-custody deaths and more effective guidelines for police officers.