Capt Johannes Ramphora, police spokesman, says the suspects wait at the robots in First Avenue and Second Street.
“They will wait there until the robot turns red before they strike,” he says.
The suspects smash the windows and grab what they can from the vehicle.
Ramphora says it happened three times at the same streets in three weeks.
During all three cases, the suspects have grabbed a handbag, cellphone and cash from the vehicles.
The police urge the community to be vigilant and rather to keep the valuable items where they are not visible.