LEWISTON – Detective Trevor Campbell stood flanked by two fellow policemen who supported his arms.

An officer stood behind Campbell, pointing a yellow plastic gun at his shoulder. A red dot danced down Campbell’s back. Then came the warning: “Taser! Taser!”

A loud pop, then two coiled wires shot out and lodged themselves in the muscle in Campbell’s back. He cried out in agony, then staggered to the mat, collapsing onto his stomach. A buzzing of snapping sounds lasted about five seconds as electricity coursed through the wires from gun to man, incapacitating him.

Campbell was felled by a weapon he is expected to start carrying next week, the latest tool in law enforcement. It’s aimed at lessening the number of injuries to cops and to the unruly people they often encounter in their line of work.

On Wednesday and Thursday, Lewiston police officers learned how and when to use the new gadgets that look like something from “Star Trek.” About 20 uniformed beat officers are scheduled to pick them up at the start of their shifts Monday along with their radios, said Sgt. Adam Higgins, who is overseeing training. He teaches defensive tactics to department officers.

Because the Tasers are meant to subdue uncooperative people, police won’t need the telescoping batons they’ve been carrying, Higgins said.

The gun looks like a water pistol so it can’t be mistaken for a firearm, Higgins said. A battery powering a microphone and camera linked to a built-in computer chip snap into the handle so that any use of the gun can be captured in multimedia. Two fine copper strands that can stretch 21 feet are coiled in a cartridge that snaps onto the tip of the gun’s barrel. The wires connect to two electrodes that can be used directly on the skin of the person being shocked. That’s called a “drive stun,” Higgins said.

Officers were told to use the Taser gun when deadly force isn’t needed. Otherwise, they should rely on their side arms, Higgins said, especially if the person is armed with a deadly weapon. A Taser is non-lethal, he said.

Using a Taser doesn’t require any direct contact. That should lead to fewer casualties.

“This prevents us from being injured and them from being injured,” he said.

Campbell was one of two Lewiston officers who volunteered to be shot by a Taser. Although it’s not mandatory, Higgins said he recommends any officer who might use the gun know what it feels like to be on the other end.

Higgins knows what he’s talking about. In learning how to train others, he felt the jolt of electricity drop him.

“It’s extremely devastating,” Higgins said. “It’s a long five seconds.”

During that time, you can’t move, he said. “It locks you right up.”

Afterward, you have completely normal function, he said. No lingering effects.

People who have been hit once are generally compliant, he said.

Technology isn’t cheap. The guns cost about $1,200 apiece, plus holsters and training. The disposable cartridges cost about $20.

More than 50 Maine law enforcement agencies and departments are carrying some form of the Taser, Higgins said.