The Mysterious Police Car

Mrs. Earlene Roberts, the housekeeper at Oswald's lodgings gave testimony to the Warren Commission in 1964. She stated that when Oswald came back to his room at about 1pm, 30 minutes after he allegedly killed Kennedy, a police car (number 207?) with two uniformed policemen pulled up outside the house, honked the car horn twice and then moved on. This seemingly strange act was never explained or properly investigated by the Dallas police or FBI. Was it some signal to Oswald?

In fact the Dallas police claimed that it wasn't one of their cars as they could account for all their cars at that time!