Justin J. Johnson faces multiple charges of aggravated robbery. The girl was referred to the juvenile justice system and her identity is not being released.
The robberies mostly took place April 6 at a Valero store on FM 529, a CVS store on W. Little York, a Murphy's USA on Fry Road, a Valero on Barker Cypress Road and a Valero store at West Road. After brandishing a gun, authorities say the robbers got cash and other items.
At one store, officials say a witness said Johnson told an employee, "My girl is about to rob the store, you better leave." The employee did so.
The defendants also are thought to be responsible for an April 7 carjacking in the area and a robbery in Fort Bend County.
They were arrested by Precinct 4 constable's deputies after an elderly resident of the area called 911 to report a suspicious vehicle parked in her neighbor's driveway. The vehicle had been stolen and contained credit cards belonging to one of the robbery victims.