Although more than a year has passed since a man died in Montgomery County police custody after a Taser was deployed during an arrest, doubt remains about the safety of the device.

Police officers should change their procedures in how they deal with people exhibiting erratic behavior to reduce the need for Tasers and, ultimately, prevent deaths, said Mike Mage, a chairman of the Montgomery County American Civil Liberties Union.

“When you see a disturbed person or unusual behavior occurring, your first thought should not be, ‘This is illegal, and we have to arrest this person,’ ” he said. “It’s not really a crime situation. It’s a medical emergency situation. . . . Their first response should be to get medical backup.”

Mage also believes that, if police continue to use Tasers, they should be made to carry defibrillators in their patrol cars to treat episodes of cardiac arrest that he said could result from use of the devices.

Officer Scott Davis, a Montgomery County Police Taser instructor, dismissed Mage’s idea. He cited county police policy, which states that Tasers may be used only to protect officers or subdue a potentially dangerous or violent person when the officer believes that other methods have been or will be ineffective. Officers often deploy Tasers on suspects who could harm themselves or others, including responding officers, Davis said.

“When that person is completely violent and when they’re attacking us, there’s no other way to go; we have to subdue that person,” he said. “Our job is to try to get that person into some kind of restraint and keep them from hurting themselves or others.”

Neither Davis nor David Fowler, Maryland’s chief medical examiner, had ever heard of anyone suffering from cardiac arrest as a direct result of being stunned by a Taser.

Delric Tyrone East, 40, was the most recent person to die in county police custody after a Taser was used in his arrest. Karreem A. Ali died in October 2010, the only other person to die in police custody after a Taser was used in an arrest. But these deaths, while troubling, hardly constitute a pattern, Davis said.

County police used Tasers in 171 incidents last year and 62 this year as of last week, Davis said. Of the 1,159 officers on the county police force, 580 are certified to carry the X26 model Tasers used by the department, Davis said.

Electronic control devices such as Tasers incapacitate targets by delivering a high, 50,000-volt shock at a very low .162 amps, according to Taser International specifications.

The shock temporarily disables a person’s central nervous system and causes uncontrollable spasms in muscle tissue, according to the X26 manual. Although such a shock usually is enough to drop even the most agitated person immediately, it is not sufficient to interrupt a person’s heartbeat, Fowler said.

Fowler believes that restraint might be the true cause of most sudden in-custody deaths, not Tasers. Whereas the effects of a shock-induced heart problem would take place immediately after the shock, most in-custody deaths take place as long as a half-hour after the person has been subdued and restrained, Fowler said.

“Most of these people are arrested, they stop struggling, and then, several minutes later, police notice that they are unresponsive,” Fowler said. “It’s not the Taser that’s common to all of these deaths. It’s the restraint.”

Fowler believes the deaths can be better labeled as a medical phenomenon called excited delirium. The fear of being restrained — which often is exaggerated by the presence of drugs and other intoxicants in a person’s bloodstream — and preexisting heart conditions are the main catalyst for such deaths, he said.

Although not fully understood as a medical condition, symptoms of excited delirium often include a sudden spike in core body temperature within a half-hour of restraint, Fowler said. Some hospital patients reached 108 degrees, he said. Reports of such deaths date to the 19th century, from mental patients subdued by orderlies, Fowler added.

A study of the phenomenon as it related to police officers was undertaken in the 1980s after Seattle-based medical examiner Donald Reay noticed a pattern of prisoners dying shortly after arrest. Reay quickly determined that hog-tying, in which a person’s hands and legs are tied together behind their backs, was causing the deaths, Fowler said.

“So they stopped hog-tying people, and do you know what happened? People kept dying,” Fowler said, adding that, in the decades since, everything from officers putting pressure on a person’s chest to pepper spray has been blamed for sudden in-custody deaths.

“Then you end up with the Taser coming along and, all of the sudden, they are the reason people are dying,” he said. In reality, he thinks, the Taser is “just the new kid on the block.”

For many officers, such as Davis, there’s no perfect solution to excited delirium cases because the condition is not easily distinguished from drug-induced psychosis and often strikes without warning. Part of every Taser-certified officer’s training involves watching video footage of an in-custody death event and its handling by the police agency.

Emergency rescue officials are looking for new ways to reverse the near 80 percent mortality rate linked to confirmed excited delirium cases, but without sufficient technology to distinguish excited delirium from other emergencies, progress is slow, said Assistant Chief Scott Graham, a 24-year veteran emergency medical technician with the Montgomery County Fire and Rescue Service.

“I have no tool in my toolbag to diagnose you with excited delirium as opposed to cardiac heart disease,” he said. “I could assume that it’s excited delirium, but we have a very strict protocol that tells us how to treat a person experiencing cardiac symptoms. . . . If your heart is going too fast, I use this drug; if your heart is going too slow, I would use this drug.”

One of the most common treatments to stimulate a stopped heart is to inject it with adrenaline, a widely practiced procedure that actually would hasten death in cases of excited delirium, Graham said.

“Our changes in treatment are driven by medical research,” Graham said. “Unfortunately, many, many, many people may die of a particular disease before practices are changed.”

EMTs were the first to respond to the scene after East, who was later found to be high on PCP, drove his car into a concrete barrier on Route 29 in Briggs Chaney, according to police reports. East was fighting medical personnel as they were trying to remove him and his girlfriend from the vehicle when he was Tasered by responding police.

“One death is obviously unacceptable,” Davis said. “But then again, there’s what they call the perfect storm, and we see that nationally. You can do everything right, and that person will still end up dead.”