BIG PINE KEY, Fla. -

Two sisters riding in the same car were charged with driving under the influence late Saturday.

A Monroe County Sheriff's Office deputy saw a vehicle swerving, changing speeds, and braking suddenly. He turned on his lights and siren and the car stopped suddenly in the lane of traffic.

Through the back window, he could see the driver and passenger quickly switch seats.

Steffany Miranda, 18, and Vanessa Miranda, 24, were both at some point in control of the vehicle, according to investigators. They were both charged with driving under the influence of alcohol.