When New Haven Police Department officers could not subdue a man outside Toad’s Place late Saturday night, they used one of the newest weapons in their arsenal: the Taser.

Two years ago, police would not have had this option — a few NHPD officers were first armed with the stun guns in July 2007. Since they were introduced to the department, NHPD spokesman Joseph Avery said, the guns have been used in 85 incidents as of Tuesday. While Avery said Tasers — which deliver a 50,000-volt shock — have helped officers, their use is highly controversial.

The NHPD began using Tasers after a series of police shootings in 2004, which prompted the Board of Aldermen to form a task force to explore less-than-lethal weaponry. The Yale Police Department, meanwhile, does not carry Tasers.

Avery said the Tasers have cut down on both officer and subject injuries, as they are less deadly than other options. Of the 85 incidents of Taser use by the NHPD, Avery said there has not been a single formal complaint about the officer using unnecessary force.

“The Taser X26 may be used when a subject(s) actions are perceived by the officer to be of Active Resistance or greater,” according to NHPD regulations. “The Taser X26 may also be used to prevent persons from harming themselves or for defense of yourself or a third party against vicious attacking animals.”

Many precautions are in place to ensure the Tasers are used appropriately, Avery said. Every time the weapon is energized it begins to record audio and video, which is later reviewed. Every officer who is armed with a Taser goes through eight hours of training each year on the proper use of the weapon, Avery said.

But in 2007, 26-year-old David Mills died after being shot five times by Hamden police with a Taser. Mills’ mother has sued the Hamden police and the officer who stunned him, claiming the police used “unreasonable force” on Mills, though the New Haven State’s Attorney determined the police had acted appropriately in the Mills incident.

“People die from the Taser on a fairly regular basis,” Jonathan Einhorn, who is representing Mills’ mother, said in an interview on Wednesday.

According to a December 2008 report by Amnesty International, 334 people have died after being shot by Tasers in the United States between 2001 and August 2008.

The report also notes that in fewer than 50 incidents was a Taser found to be a contributing factor in the death. In only a couple of disputed cases has a Taser been found to be the primary cause of death, said Steve Tuttle, vice president for communications at Taser International, which manufactures the Tasers used by the NHPD.

Another criticism of Tasers came from the U.N.’s Committee against Torture, which said in 2007, “The use of these weapons causes acute pain, constituting a form of torture.”

Tuttle disputed this classification.

“The U.N. Committee based its statement on the fact that a Taser device provokes ‘extreme pain,’ ” he said. “By invoking such a strict definition, each and every tool available to law enforcement officers worldwide to end a use-of-force confrontation, including pepper sprays, batons and even fists, could then constitute a form of torture.”

Einhorn said there have not been enough studies done on the safety of the guns for them to be considered safe. Most of the studies that have been done, he added, have been conducted by Taser International.

Tuttle, however, said 80 percent of the more than 240 studies that have been conducted were done independently of Taser International, and showed that Taser devices are far safer than any other weapon on an officer’s belt.

According to a Taser International press release, 390,000 Tasers have been sold to 13,900 law enforcement and military agencies.