UPDATED | October 16, 2017  2:15 PM

WACO, Texas (AP) — Steel barriers and sheriff’s deputies surrounded the courthouse in Waco, Texas, in a show of heightened security as the trial began for an alleged leader of the Bandidos biker gang in connection to the deadliest shootout between biker groups in U.S. history.

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But experts say the trial — the first stemming from the fatal May 2015 shooting — could reach far beyond the single case, as the government tries to convict other leaders and dozens of members.

It has been nearly 2 ½ years since a confrontation between the Bandidos and the Cossacks left nine bikers dead and 20 wounded outside a Twin Peaks restaurant in Waco. Local police arrested 177 bikers after the mayhem, and more than 150 people were eventually charged.

Federal investigators also indicted the president and vice present of the Bandidos — though not for the shooting in Waco — and are set to bring them to trial next year. Five other Bandidos have pleaded guilty to federal charges.

The first to stand trial in Waco is Christopher “Jake” Carrizal, the Bandidos’ Dallas chapter president, whose trial began last week. Experts say a conviction in the case could have a domino effect by convincing other bikers to plead guilty and testify.

“Guys who are less involved start to turn and lead prosecutors all the way to the top guys,” said Charles Falco, a law enforcement instructor and a former informant on California biker gangs for the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.

Carrizal, 35, is charged with directing organized criminal activity that led to a violent brawl at the restaurant in Waco on May 17, 2015. If convicted, he could face a maximum sentence of life in prison.

The outcome of his trial also could affect federal prosecutions of former Bandidos president Jeffrey Pike and vice president John Portillo. While the Waco shootout isn’t mentioned in the federal indictments against both men on racketeering charges, including ordering killings and assaults, government witnesses have discussed the Waco incident in pretrial hearings, court records show.

“Anything presented in state court, where the standard for getting evidence admitted in lower, can be used in the federal trial,” said Heidi Lambros, a criminal law public defender in Chicago.

Biker gangs are a small but violent criminal force in the U.S., with some 44,000 members or associates of a handful of “outlaw” gangs, according to a 2015 FBI report. The Bandidos, founded in Texas, is among the largest of the criminal gangs, along with the Hell’s Angels and a couple of others.

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The Cossacks were considered less violent until the Waco confrontation.

The start of any Waco trials was delayed by the enormous volume of evidence and several bikers’ attempts to have their cases dismissed. Defense attorneys argued the bikers were hastily arrested and charged without consideration of individual culpability. Carrizal’s attorney,

Casie Gotro, has said that the McLennan County District Attorney’s office denied her client access to certain records and may have “tampered” with evidence.

Investigators recovered hundreds of weapons after the shooting, including firearms, knives and brass knuckles strewn across the restaurant and adjacent parking lot. State prosecutors said they were also awaiting results from DNA tests to determine who held the weapons used in the deaths and assaults.

Carrizal’s trial was scheduled to begin Sept. 11, but it was reset after the first presiding judge was recused over the appearance of potential bias in favor of the state. Carrizal unsuccessfully sought the removal of the replacement judge, too.

Gotro said the tight security at the Waco courthouse during Carrizal’s trial was having a chilling effect on public access to the trial.

Last week, Gotro asked presiding state District Court Judge Matt Johnson if there had been specific threats that required additional security for the trial. She said a review of jury questionnaires showed that half of the potential jurors were scared to be there.

Johnson deferred to McClennan County Sheriff Parnell McNamara, who told The Associated Press on Thursday that “I have to do everything I can to provide safety to the citizens.”

McNamara declined to say whether the measures address a specific threat.

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