A trial is underway amid heighted security in Texas for a local leader of the Bandidos biker gang in the first trial stemming from the deadliest shootout between biker groups in U.S. history.

Investigators say the May 2015 shooting was sparked by a confrontation between the Bandidos and the Cossacks outside a restaurant in Waco. The shooting left nine bikers dead and 20 wounded. More than 150 people were eventually charged.

The first to stand trial in Waco is Christopher "Jake" Carrizal, the Bandidos' Dallas chapter president. The 35-year-old's trial began last week. Experts say a conviction could have a domino effect by convincing other bikers to plead guilty and testify.

Carrizal is charged with directing organized criminal activity that led to the violent brawl. If convicted, he could face up to life in prison.