CASE 6 – Taking the haunt out of the Ghost cars
Taking the haunt out of the Ghost cars
My client was caught in a speed trap. The trapping device that was used was situated in an unmarked law enforcement vehicle, which was popularly known at the time as the “ghost car”.
Since speed is calculated by dividing the distance travelled by the time that it took for travelling the distance, the trapping device had a facility that measures distance and a facility that measures time. I will refer to the facilities as the “distance meter” and the “timer” respectively.
It worked as follows: When the officer notices a vehicle that appears to be speeding, he follows the vehicle and when the vehicle reaches a landmark, such as the vertical structure of a bridge, the officer activates the timer, and thereafter activates the distance meter when the ghost car passes the same landmark. The ghost car then continues to follow the target vehicle and when the target vehicle passes another suitable landmark, the officer deactivates the timer. The machine is alleged to calculate the time that it took for the target vehicle to travel between the two landmarks. When the ghost car passes the second landmark the officer deactivates the distance meter and the machine is alleged to then calculate the distance between the two landmarks, and thereafter immediately to compute the speed of the target vehicle with the formula, speed equals distance divided by time.
My opening strategy in the case was to apply to court that we, the presiding magistrate, the prosecutor, and I, take a trip in the ghost car. The magistrate agreed and we became a court on wheels. Perhaps I should say that it was six wheels of justice that rolled into action, four wheels on the road, the spare wheel and the steering wheel. I asked that we visit the “Golden Mile” on the Durban waterfront and take the ghost car through its paces on the stretch marked as the “Measured Mile” that started just in front of the building of the Natal Command. At my request the officer maintained a constant speed of 60 km per hour and activated the devices when passing the signposts that marks the start of the measured mile, and deactivated it at the signpost that marks the end of the measured mile. The results of several tests were all rather pathetic.
But lo, the magistrate (one Gordon) did not seem to see the nail in the coffin of the state’s case, and I realised that I will have to attack the technical evidence of the expert.
The electronics expert that was called by the state proved to be a big disappointment for both parties. Since I was looking forward to a challenging intellectual exchange with the electronics boffin, I brushed up on the basics of electronics (having previously built an oscilloscope) and I revisited the basic laws of electricity, transistors, resistors, capacitors, impedance, etc. That, however, proved to be a vast overkill because when I started to cross-examine the expert, it soon became clear that he was an electronics technician, who has no knowledge of the design of electronic circuits. He has in any event moved into sales a number of years earlier and appeared to have forgotten more about electronics than he ever knew. He was therefore no challenge and I successfully argued that he is not an expert and the state lost its case
Not long thereafter the prosecutor joined my law firm as my article clerk.