Three Alaska bowhunters are charged with using an airboat -- named the "Critter Gitter"-- to chase down a moose as they shot the young bull with arrows this fall at Maud Lake, southeast of Palmer.

A witness tipped off Alaska Wildlife Troopers in August that he had seen the men "assassinating a moose," trooper Ernest Brent wrote in an affidavit supporting the misdemeanor charges, filed separately against Matthew Keplinger, 56, in August; Troy Martin, 46, in September; and Robert Nash, 48, in October. Troopers issued a dispatch on the case Wednesday.

The alleged wildlife crimes happened in Game Management Unit 14A. It is illegal to use a boat in Alaska to harass wildlife, and in the area in question it is illegal to shoot big-game from a boat.

Lawyers for the men say they plan to fight the charges.

The witness gave troopers part of a license plate for a black Chevrolet pickup towing the Critter Gitter, both of which turned out to be registered to Martin. And another witness came forward with video and photos, Brent's affidavit says.

The second witness said he was closer to the bull -- "approximately 127 yards," the affidavit says -- and the bowhunters were more like 150 yards when the others first launched arrows at it. "(He) heard the arrows hit weeds right as they were shot and (his) observation of the moose was that it was not hit before the individuals began chasing it with the airboat."

The man said they were circling the bull in the airboat, with the motor running, trying to cut the moose off so they could shoot arrows at it.

"Trooper Brent reviewed the video, which showed an airboat chase a running moose for almost five minutes through a swamp, which was the entire length of the video," the affidavit says.

The troopers went to talk to Martin, a Palmer resident, and found the Critter Gitter and the black truck in Martin's driveway. Martin said he believed he and Nash hit the moose with their first shots, that it was limping and then swimming as they chased it in the airboat and put a total of four arrows in the animal, the affidavit says.

The wounds included one to the rump -- not a kill-shot, Trooper Brent noted when he inspected the meat at Mat Valley Meats, where Martin had taken it for processing. There were three other obvious holes in the rib cage, Brent wrote.

Troopers talked to Nash, also a Palmer resident, and Keplinger, who lives in Kodiak.

Nash said he estimated the moose was 52 yards away and that his first arrow missed, the affidavit says. The moose "crunched up" after Martin's shot, which appeared to have hit, Nash said. Keplinger drove the boat, Nash told troopers.

"Nash said he thought the animal would have died from the initial arrows if they had not have chased it," Brent wrote in the affidavit. "Nash said the boat continued to go for about 45 seconds to a minute before it would stop completely. Nash couldn't tell me if the engine was completely off before they shot."

Trooper Daniel Valentine interviewed Keplinger in Kodiak, and Keplinger said the men noticed a spike-fork bull about 6 p.m. that night. Keplinger put the moose at 45 to 50 yards away and said he fired up the boat to go pick up the other two hunters, who were not onboard when they first shot, the affidavit says. "Keplinger stated the moose was walking along the edge of the lake and they were cutting it off from going in to the woods ... Keplinger stated he would accelerate the airboat to cut off the moose and if the range was right, turn off the key so they could shoot, making every attempt to recover the wounded animal."

Troopers said in the statement Wednesday that they have seized the moose meat, compound bows, the airboat, and its trailer. Martin, Nash and Keplinger have been summoned to appear in Palmer court to explain to a judge just exactly what was going on.

Martin's lawyer, Brent Cole, would not talk about specifics from the case.

"Is he going to go in and just plead guilty? No," Cole said. "It is a one-sided investigation, and they haven't said both sides of the story, but at this point it isn't really appropriate to make a comment."

Chadwick McGrady, Nash's lawyer, said the men were ethically obligated to get the moose once they'd wounded it initially and the requirement under the game regulations to make a "reasonable effort" to recover it meant they needed the airboat.

"They did what any ethical hunter would do, and they pursued it," McGrady said. "Not only law, it's just the right thing to do because no one wants a wounded animal running around suffering any longer than it has to. And also, the spoilage of the meat."