A Wisconsin man, who along with his three friends is suspected of illegally slaughtering as many as 100 deer in what prosecutors call an unprecedented "thrill-kill" spree, faces up to six months in jail.

Nathan Blaha, 20, of Hillsboro, Wis., and his accomplices allegedly wandered the backroads of Richland County in a pickup truck, stunning deer with a light before shooting them and leaving their carcasses to rot in what he called a contest to “get the most deer,” according to court documents.

"This is the antithesis of hunting," Richland County District Attorney Jennifer Harper told FoxNews.com Thursday. "This is thrill killing."

Blaha, and his alleged accomplices, 17-year-old Steven Blaha and 18-year-old Brogan Gillingham, face criminal charges in the December killing spree, when the suspects allegedly shot whitetail deer from the road after dark and without a license. A fourth suspect, a juvenile male who has not been named, was issued citations, Harper said. Steven Blaha can be tried as an adult under Wisconsin law.

According to a criminal complaint obtained by FoxNews.com, the older Blaha, who is believed to have done most of the shooting, confessed to killing 20 to 30 deer “this past fall and during the 2011-2012 gun deer season illegally.”

"The reason I was doing this was because we all kind of had bets who could get the most deer," Blaha said in a written statement to Conservation Warden Mike Nice of Richland Center.

But Blaha's co-defendants estimated the number of slain deer to be much greater, telling authorities they believe he illegally shot and killed as many as 100 whitetail deer within the past two years.

"There have been cases of shining and road hunting," Harper said, "but nothing to this extent." Deer shining is the practice of using a high-powered, hand-held light to see the animal at night. The bright light is commonly used by hunters to track the location of deer herds at night when the animals are most active.

The 20-year-old Blaha is charged with three counts that each carry a penalty of up to six months in jail and a $1,000 minimum fine. He also faces revocation of hunting rights for the next nine years.

The investigation into the illegal deer killings began when private landowners reported hearing gunshots at night and finding deer carcasses on their properties.

Licensed deer hunting is a time-honored tradition throughout the scenic landscape of Richland County, and other parts of the state, during a nine-day period around Thanksgiving. Residents must obtain a license and conform to various regulations and ethical rules. Hunters can use only certain kinds of weapons, for example, and are prohibited from shooting after sundown.

The suspected illegal slaughtering of deer by Blaha violated all the rules of hunting, authorities said, and has since outraged many hunters and conservation groups who claim Blaha may have depleted the herd and brought unfair notoriety to the sport.

"Some people hear this story and they think that’s what hunters do," said Jeffrey Schinkten, president of Whitetails Unlimited, a national conservation organization based in Sturgeon Bay, Wis.

"He’s not a hunter. He’s a game thief," Schinkten told FoxNews.com. "I hope they throw the book at him. It’s unconscionable."