In one case, police used a Taser while responding to a domestic dispute in Kona. In the other incident, officers used the device in East Hawaii but police didn't release details.

Sgt. Sam Kawamoto, one of six Taser trainers on the Big Island, said at least 90 percent of West Hawai'i officers have completed the mandatory eight hours of training to use the device and now carry a Taser X26.

Tasers use compressed nitrogen to fire two barbed darts that can penetrate clothing to deliver a 50,000-volt shock to immobilize people.

Police departments across the country have adopted them, but critics allege the device is dangerous and can cause cardiac arrest.

Canada is examining the police use of Tasers after two recent deaths, including one in which a man died about 30 hours after being shocked.

The manufacturer of Taser guns, Taser International Inc. of Scottsdale, Ariz., says they have never been conclusively linked to any deaths in Canada.

The Big Island is at least the third jurisdiction in Hawai'i to adopt electronic control devices, Kawamoto said.

Honolulu and Maui police are already equipped and Kauai is in the process of training its trainers, who then will train the county's officers.

Kawamoto said police always try to get suspects to willingly accompany police when they are under arrest. But sometimes that's not possible.

"The whole purpose is to minimize injuries to us and to the subject. We don't want to get into physical confrontations," said Kawamoto.

"Say I have to arrest you and you don't agree, you are noncompliant. I don't want to fight with you because someone might get injured," Kawamoto said. "With this device, there is less of a chance of me getting hurt and there's also less chance that you will get hurt."

The device propels two stainless steel probes attached to 21 feet of copper wire that are used to release a 5-second jolt of electricity. The response in 99 percent of the subjects is an immediate freezing of muscles and falling to the ground.

"It's as if your body is going through a cramp," said Officer Chad Taniyama, also a trainer. "It's not a torture device. People who don't understand the device or the medical research might have a misconception."

There's been little opposition to the devices on the Big Island.

Kawamoto said two meetings last week in West Hawaii held to explain and demonstrate the device drew five people who had questions. Those who attended left comfortable with the idea of police carrying the stun guns, he added.

More meetings are scheduled across the island.

Earlier this month, a United Nations committee deemed some uses of Tasers could be considered a form of torture, in violation of the U.N. Convention Against Torture.

An Amnesty International report said 290 people died in the U.S. and Canada from June 2001 to Sept. 30, 2007 after Tasers had been used on them.