New Details Emerge in Matthew Shepard Murder

Laramie's Dangerous World of Methamphetamine

As a heavy user and a dealer, McKinney was well-known with the methamphetamine crowd, according to Ryan Bopp, who was one of McKinney's friends and drug associates at the time. By the fall of 1998, McKinney had blown through his inheritance and was now the parent of a new baby with his girlfriend, Kristen Price.

"I think he was really torn because it is the desperation of getting your fix or taking care of your family," Price said. In the days leading up to the attack on Shepard, she said, McKinney was using methamphetamine every day.

Bopp, who says he left Laramie and the drug world behind six years ago, told "20/20" that he and McKinney had been on a drug binge in the week leading up to the attack on Shepard.

"Aaron and I had been awake for about a week or so prior to this whole thing happening ," Bopp said. "We were on a hard-core bender that week."

Bopp also admits that a week before the murder he was so desperate for methamphetamine, that he traded McKinney a .357-Magnum pistol in exchange for one gram of methamphetamine. McKinney would later use that weapon to beat Shepard.

The Night of the Crime

McKinney told Vargas he set out the night of Oct. 6, 1998, to rob a drug dealer of $10,000 worth of methamphetamine. But after several attempts, McKinney was not able to carry out his plan.

Henderson said he thought if he could keep McKinney drinking, he'd forget the robbery plan.

But according to McKinney, when he encountered Shepard at the Fireside Lounge, he saw an easy mark.

McKinney told "20/20" Shepard was well-dressed and assumed he had a lot of cash.

Shepard was sitting at the bar, McKinney recalls. "He said he was too drunk to go home. And then he asked me if I'd give him a ride. So I thought, yeah, sure, what the hell," according to McKinney.

All three got in the front seat of McKinney's pickup, and Henderson took the wheel. McKinney told police that at some point Shepard reached over and grabbed his leg. In response, McKinney said, he hit him with his pistol. "I was getting ready to pull it on him anyway," he said.

McKinney says he asked for, and got, Shepard's wallet, which had only $30 in it. But even though Shepard handed over his money, McKinney continued beating him.

When pressed by Vargas as to why he continued beating Shepard after he had already taken his wallet, McKinney said, "Sometimes when you have that kind of rage going through you, there's no stopping it. I've attacked my best friends coming off of meth binges."

McKinney says he directed Henderson to drive the truck to a secluded spot on the outskirts of Laramie so they could leave Shepard and have time to get away. They stopped at a wooden buck fence and took Shepard from the truck.

On McKinney's instructions, Henderson got a rope from the truck and tied Shepard to a fence post. Henderson claims at some point he tried, but failed, to stop McKinney from beating Shepard further.

In a statement to the court, Henderson said McKinney struck him across the face with the gun when he tried to stop the continued beating of Shepard.

Henderson retreated to the truck, leaving McKinney alone with Shepard at the fence. McKinney tells "20/20" he fears these last blows he dealt Shepard at the fence were the fatal blows.

New Fracas Leads to Arrest

McKinney took Shepard's wallet and his shoes, got back in the truck and told Henderson to drive to town. He says his plan was to burglarize Shepard's apartment. But when they parked the truck they encountered two young men who police say were vandalizing cars. Hostile words led to a fight and for the second time that night, McKinney went on the attack.

One of the men was struck so hard his skull was fractured. The injured man's friend retaliated, slamming McKinney in the head with a small bat. Everyone fled, just before a police car happened on the scene.

Sgt. Flint Waters gave chase and grabbed Henderson. Then he discovered some key evidence that would later be used to link Henderson and McKinney to the attack on Shepard.

"I looked in the back of the truck and laying in the back of the truck was a large-frame revolver. The thing was huge, like an 8-inch barrel that had blood all over it. And there was some rope and a coat in the truck; there was I believe a shoe sitting in the front. ... Seeing that the gun covered in blood, I assumed that there was a lot more going on than what we'd stumbled onto so far," he said.