LAS VEGAS (AP) - After four years preparing, federal prosecutors hoped to prove at a trial spawned by a deadly casino brawl between Hells Angels and rival Mongols that the world's most famous motorcycle club was a criminal racketeering enterprise like the Mafia.

A conviction would have given authorities long-sought tools to bust up the Hells Angels - which prosecutors characterized as a disciplined but violent organization that deals drugs and runs guns across the U.S. and around the world.

Instead, the case skidded on procedural grounds and spun into a ditch, carrying most of a state murder case with it. Six Hells Angels pleaded guilty or no-contest to lesser charges, and the organization they insisted was just a club for motorcycle enthusiasts emerged unscathed.

The outcome surprised jurors and disappointed law enforcers.

"I don't want to see these guys get away with murder. I really don't," said Las Vegas Police Lt. Thomas Smitley, who was involved in the case even before the Hells Angels roared up the road to a hotel where the Mongols were staying.

Smitley didn't get to testify about pulling Hells Angels and Mongols leaders together to try to defuse tensions just hours before the April 27, 2002, clash marred the annual Laughlin River Run motorcycle rally.

By Smitley's account, Hells Angels leaders told him they'd take care of themselves.

Hours later, chaos erupted at the Harrah's Laughlin hotel-casino. Two Hells Angels and one Mongols member died as bikers brawled and gunfire erupted. Casino patrons and bikers dove for cover behind blinking slot machines. More than a dozen people were hurt.

Much of the fighting was captured on casino surveillance videotapes: dramatic evidence showing Hells Angels in their unmistakable leather vests shooting, stabbing and punching rival Mongols.

"That's the nature of living in the world of the Hells Angels. Violence is all around you," said Terry Katz, a retired Maryland State Police lieutenant in Linthicum, Md., who is a former president of the International Outlaw Motorcycle Gang Investigators Association.

Prosecutors told jurors in federal court in Las Vegas that Hells Angels plotted the Laughlin brawl.

Using superimposed arrows and stop-action, rewinds and freeze-frames, two U.S. attorneys and more than a dozen defense lawyers replayed multiple confrontations from various camera angles. One Hells Angels member launches a karate kick toward a Mongols member. Another fires a gun. Another clobbers a Mongols member with wrench.

But after just two weeks of a trial that had been expected to last at least two months, lawyers for 11 Hells Angels defendants sowed doubt in jurors' minds about what happened off-camera and outside the courtroom.

"At first, I remember the videos," said juror Steve Schranz, 51. "If it started and ended right there, the Hells Angels were guilty.

"But when you started dissecting the films and looking at photos, it looked like the Hells Angels were defending themselves," Schranz said. "I was leaning toward the Mongols started it."

He remembered defense lawyers pointing out Mongols members carrying duffel bags into the casino before the fighting - bags lawyers said contained weapons.

Schranz remembered a video frame stopped by a defense lawyer showing what appeared to be a foot-long knife in the hand of a Mongols member who ran away after a Hells Angels member fired a handgun at him.

A photo image stuck in his mind of a dead Hells Angels member's body left unattended in an empty driveway outside Harrah's.

And he recalled earlier security camera images of a Hells Angels member tipping a casino employee $100 two times, after twice winning at a slot machine.

"That's not a boneheaded biker individual," said Schranz, a building engineer at a Las Vegas Strip casino. "To me, that's a pretty good person."

Defense lawyers also convinced U.S. District Judge James Mahan that the government had failed to disclose key evidence that would cast doubt on the truthfulness of key witnesses in the racketeering case.

One witness was Patrick Matter, a former Minneapolis Hells Angels chapter president now imprisoned for drug dealing and money-laundering. Another was James Howard Richey, a former Phoenix-area Hells Angels chapter officer who testified as a federally protected witness.

With the jury watching, Mahan twice interrupted Matter's testimony to call it as unfair to blame all Hells Angels for the criminal acts of a few as it would be to accuse all Roman Catholic clergy members of sex abuse after the transgressions of a few priests.

Days later, Mahan told the jury to forget what they heard from Richey, saying prosecutors improperly withheld information from the defense.

Trial never resumed.

With the case teetering on mistrial, six Hells Angels pleaded to lesser charges in state and federal courts. State and federal prosecutors dropped charges against the remaining 36 Hells Angels.

Six Mongols still face state charges, including murder and attempted murder, but no Mongols were charged in the federal case.

"I was really appalled that this was the best they could do," Schranz said. "I hear they've always wanted to bust them as the current-day Mafia."

The scorecard: Forty-four Hells Angels indicted. One died, one is a fugitive and 42 ranging in age from 28 to 63, from California, Washington, Arizona, Alaska and Nevada, were arrested. They faced charges including racketeering attempted murder, which could have brought the possibility of life in prison if convicted. Eleven stood trial in the first of what was planned to be several trials.

The six who entered pleas to federal charges of committing a violent crime, battery, in aid of racketeering, did so as individuals, meaning the club was spared.

That was a crucial distinction for a corporation with an estimated 3,500 members worldwide and lucrative trademarks and businesses selling T-shirts and death's head logos.

"If you lose a racketeering case, you lose your assets to the government," Katz said. "That's why it would be so devastating."

Troy Regas, 43, a Hells Angels member from Sparks whose brother will go free, declared the outcome a victory.

"What it means to us is that the club itself has never been found to be a criminal organization," he said.

Four men pleaded guilty. Two pleaded no contest, which Mahan noted carries the same weight at sentencing as a conviction. They entered similar pleas to felony battery in a parallel state murder and conspiracy case that had not yet reached trial. Most face no more than a total of 2.5 years in prison on state and federal charges.

The U.S. attorney in Las Vegas, Daniel Bogden, and officials with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives said they're satisfied that six people were held responsible for the violence at Harrah's.

"The six primary guys were convicted," said Susan Raichel, spokeswoman for the ATF office in Los Angeles. "They knew they were going to lose their case. If there wasn't a doubt they would lose and be convicted of something, they wouldn't have pled."

Not so, said Alan Caplan a San Francisco-based lawyer whose client, former Richmond, Calif., Hells Angels chapter President Michael Smullen, 48, went free.

"The facts would have won out," said Caplan, who has represented Hells Angels members several times in the past 30 years. "This was not a premeditated event. The federal government swung and missed on trumped-up charges that didn't bear any relation to reality."

Others saw the trial's outcome as an example of the kind of organized crime that prosecutors had hoped to prove and break apart.

"Individuals were willing to take the fall to protect the name and the image of the group," said Julian Sher, co-author of a book about the Hells Angels called, "Angels of Death: Inside the Biker Gang's Crime Empire."

"In a delicious way, their willingness to fall on the sword for the club proves that is a disciplined, organized group," Sher said from his home in Montreal. "The question is whether it was criminal."