MARIETTA, Ga. -- The head of the Georgia NAACP called Monday night for a state investigation into the sentences given in the so-called "Barbie bandits" bank theft case.

Edward DuBose said he is asking state Attorney General Thurbert Baker to look into why a Cobb County court gave the two white women in the 2007 bank heist less time in jail than the two black men in the case.

Last month, Cobb County Superior Court Judge Mary Staley sentenced Heather Johnston, 20, 10 years probation after she pleaded guilty to a charge of theft by taking and cooperated with prosecutors. The judge gave Ashley Miller, 19, two years in jail and eight years probation.

Their accomplices, both black, received tougher sentences.

A jury convicted Michael Chastang, 28, to 10 years behind bars for being the mastermind of the robbery. Chastang's case went to trial after he pleaded not guilty. Bank teller Bennie Allen III, 23, pleaded guilty and was sentenced to five years in jail after prosecutors said he was not cooperative.

Chastang is also serving 15 years on drug-trafficking charges not related to the bank robbery. Allen was on probation for a drug conviction.

Johnston and Miller -- both former exotic dancers who went by the stage names "Charlie" and "Adrienne" -- were nicknamed the "Barbie Bandits" after they were videotaped wearing sunglasses and laughing as they appeared to rob a Bank of America branch in Acworth of $11,000 in February 2007. They admitted plotting with Allen to fake the robbery. After the heist, the women went on a shopping binge that included a stop in a hair salon.