TULSA, Oklahoma - Tulsa Police locked up eight gang members accused of a string of extremely violent robberies Thursday.

The investigation took more than a year and involved Tulsa's robbery unit, the FBI, and the Northern Oklahoma Violent Fugitive Task Force.

The Grand Jury's indictment names Vernon James Hill, 26; Christopher Darnell Lewis, 23; Deandre Antonio Hopkins, 22; Marquis Deron Devers, 23; Dontayne Dejay Tiger, 22; James Miller, 23; Kenneth Lee Hopkins, 23; and Dejuan Legmar Hill, 23, all of Tulsa.

Police said all eight men are Hoover Crip gang members, and they robbed banks, pharmacies, and credit unions.

Their crimes included the largest bank robbery in Tulsa history.

Investigators say these were the type of organized, professional, takeover robberies that are always dangerous.

Last September's robbery of the Tulsa Municipal Employees federal credit union was the largest in Tulsa's history, when the suspects made off with $170,000.

The men went in, wearing masks, carrying guns, shouting orders, jumping over the counter, and even fired a shot that broke a glass partition near a teller before they headed for the vault.

Police said the eight Hoover Crip gang members have been robbing Tulsa businesses since 2009, but that has all come to an end. All eight are now behind bars and facing federal indictments.

"This is a good day for the citizens of Tulsa, obviously," said Sergeant Brandon Watkins, of the Tulsa Police Department.

"These guys have been extremely busy since 2009, committing a lot of extremely violent robberies."

Police said the robberies often involved two, three, or four gang members at a time.

They said they robbed the IBC bank at 42nd and South Garnett in August of 2009, as well as the Dooley Pharmacy in West Tulsa in February of 2010, the T. Roy Barnes Pharmacy, and the Metro Pharmacy using stolen vehicles as their getaway cars each time, always demanding not just money, but drugs.

Police said they also robbed the Arvest Bank at 218 South Memorial in November of last year.

Robbery detectives say they haven't seen anything like this crew in decades.

"Does make this unique, to have this many people committing this many crimes over this period of time," Sergeant Watkins said.

So what were these suspected robbers doing with the money they stole?

Detectives said they were using it to pay their lawyers to work on their other cases.

Police said the men may have made some money in the short term, but if a jury finds them guilty, they could spend the rest of their lives behind bars.