Twelve people were charged Wednesday in a large-scale gang investigation that resulted in 23 felony charges for drug-related crimes.

According to documents filed in 3rd District Court, the Salt Lake Metro Gang Unit investigation centers on the actions of alleged gang leader Russell Thornwall. All of the 12 people charged made various cash or drug transactions with Thornwall during the week prior to June 20, court documents state. Thornwall had been the subject of a gang unit investigation for several months, unit supervisor and Salt Lake County Sheriff's Sgt. Paul Brenneman said.

Thornwall, 23, died June 20 after a shootout with police in the parking lot next to a Murray bar. Police say he and several other men were involved in a home-invasion robbery that night and when police officers tailed the getaway car to the parking lot, Thornwall bailed out and opened fire. Officers returned fire, but did not injure Thornwall, who disappeared behind an automobile body shop and fatally shot himself, Murray police detective Rob Hall said.

Prior to the incident Thornwall was awaiting a first-degree murder trial for his role in the 1997 drive-by shooting of Kelly (Nick) Seal, 16. Court documents also state he was involved in two separate drug dealings as the focus of an ongoing police sting.

Among the charges filed Wednesday were first-degree felony distribution charges against Timothy Dallis Swope, 36, and Jamie Marie McMonigle, 23. Both were previously in jail on outstanding warrants and $1 million cash-only bails were set along with the new charges.

Another of the 12 charged is Michael "Angel" Martinez, a paraplegic who has already been convicted of murder, a first-degree felony, for driving the getaway car in the 1999 slaying of Michael Moya. Martinez is currently incarcerated in the Salt Lake County Jail and has also been charged in connection with the home-invasion robbery that ended with Thornwall's death.

The nine others charged remained at large with $50,000 or $100,000 cash-only warrants issued for their arrests Wednesday.