A 26-year-old Hamden man died Saturday morning after being shocked by a Taser stun gun, raising new concerns about the safety of such weapons just as the New Haven Police Department readies 50 stun guns to go into service.

A spokesman for the Chief Medical Examiner’s office said Monday evening that the cause of the man’s death has not yet been determined, and Hamden police said there was no information indicating that the Taser contributed to the man’s death. But given the controversy surrounding New Haven’s introduction of stun guns, the incident could cause increased apprehension as the Board of Aldermen decides whether to arm the rest of the NHPD with stun guns beyond its initial pilot program.

Police found David Mills early Saturday fighting with another man on Helen Street in Hamden, about three miles up Dixwell Avenue from downtown New Haven. Mills spoke incoherently of demons, claimed to be on angel dust and punched, kicked, and bit officers who were attempting to detain him, police said. An officer shot Mills with a stun gun after he became increasingly aggressive, according to police.

He was taken to Yale-New Haven Hospital and pronounced dead about an hour after the incident, police said. An autopsy of the man was conducted Sunday but awaited toxicology results, police said, and a spokesman for the Hamden Police Department could not be reached for further comment Monday evening. Extremely high doses of the hallucinogen PCP — commonly called “angel dust” — can cause death, though PCP abusers more often die in accidents caused by their delusions than by the drug’s effect itself, according to the National Institute on Drug Abuse.

Mills’ death comes just as 50 new Tasers are to hit the streets this month as part of an NHPD pilot program. The yearlong trial was suggested by the city’s Deadly Force Task Force in November and subsequently approved by the Board of Aldermen.

The stun guns are not yet in use in New Haven, NHPD spokeswoman Bonnie Posick said Monday. Officers are still undergoing training, and the department is finalizing its policies regarding the weapons, she said.

Though the Tasers are to be implemented under a pilot program only, their proposed use in New Haven — and elsewhere — has been controversial. While Taser International maintains that the 50,000-volt shock caused by a Taser’s firing is not nearly strong enough to cause arrhythmia in the heart or cardiac arrest, some organizations, like Amnesty International, have questioned stun guns’ safety.

Ward 23 Alderman Yusuf Shah, the chair of the task force and a supporter of the stun gun pilot program, said the stun guns will provide a less dangerous option for police to use in lieu of conventional firearms, and that the Hamden incident should not serve as a condemnation of the weapons, at least not until the medical examiner has issued his report.

“I think the key to all of these issues is a coroner’s report,” Shah said. “That’s what I would wait on before making a definite comment about safety and security with respect to these tools … [but] if the coroner’s report indeed said that this person died as a result of being shot, then that’s something we’ll want to look at.”

In Hamden, stun guns have been used for several years without much concern, said Robert Westervelt, chairman of the Public Safety Committee of Hamden’s Legislative Council. In the Hamden Police Department, all officers who are to be armed with Tasers are shocked by the weapon as part of their training, and even one town councilman requested to be shocked by a Taser in order to feel the weapon’s effects, Westervelt said.

Even if there are concerns about this weekend’s incident, any suspect struggling with police would much rather be shot with a Taser than shot with a firearm, Westervelt said.

But Roger Vann, executive director of the American Civil Liberties Union of Connecticut and a member of the New Haven Deadly Force Task Force, did not support the committee’s recommendation of the stun guns because of safety concerns. He could not be reached for comment on Monday.

“The jury is still out on Tasers,” Vann said in November. “Given the continued controversy about Tasers, it would be inappropriate that this task force that was charged with [facilitating] a reduction in lethal force [recommend them], because I just don’t buy that this is a less lethal weapon.”

Taser stun guns have been reported as a contributing factor in about 20 deaths, a manager for Taser International said this fall when the city was considering adopting the weapons. In two cases, medical examiners ruled the stun guns to be the immediate cause of death, but both those autopsy reporters have been refuted upon further review, the manager said.

Two Connecticut men — one in Milford and another in New Britain — died last year after being shocked by police stun guns. Both deaths were ruled to be the result of drug overdoses. As of last year, more than 70 police departments in Connecticut, including the State Police, equip at least some of their officers with stun guns, according to the General Assembly’s Office of Legislative Research.

—The Associated Press contributed reporting.