Monday, April 25, 2011

Little black boxes

Scott Greenfield at Simple Justice wrote recently of a gentleman who proved that the cameras used to catch speeders in Prince Georges County (MD) aren't quite as accurate as portrayed by the manufacturer and the local constabulary.
Given a half-decent presentation by some "expert" getting a biweekly check by a manufacturer, police and municipalities are sold on the irrefutability of  machines to ascertain violations of law.  That same "expert" then trots into court, sells a judge on the conclusiveness of the toy purchased in bulk by law enforcement and, like magic, it convicts.  There's no arguing with magic boxes and pictures with stamps on them.  When the box says you did it, what judge can disagree? 
We have become blindly reliant on the accuracy and irrefutability of technology.  While some, perhaps even most, are indeed accurate when properly used, calibrated, cared for, when the optimal conditions exist and nothing interferes or impairs the sterile laboratory settings under which their viability is determined, they don't necessarily remain accurate when on the road. 
Mr. Greenfield then goes on to talk about the problem with judges (and jurors) relying on the mystical information provided by little black boxes. We don't require the police who operate the various black boxes (radar, laser and breath test machines) to have any idea how the blasted things work. We listen to these officers describe the length and rigor or their training -- which apparently teaches them nothing more than how to turn on the machines and input some information.
What about those sweet black boxes into which one blows, awaiting a digital readout that will let you know whether you will be sleeping in your own bed that night or find your face on some registry of people who will be permanently unemployable?  There have been a multitude of efforts to find out exactly what happens inside those boxes, and maybe some day somebody will figure it out.  In the meantime, does it occur to any judge who has ever admitted evidence from a mysterious black box that he will convict a person based on conclusory evidence by some outside equipment vendor, the accuracy of which may be completely assumed? 
Seriously, judge, if have no clue how something works, generically or under the specific circumstances presented, how can you blindly assume that magic boxes, cameras, whatever, provide a sufficient basis to sustain a conviction?
We are convicting people daily on the basis of information provided by some magical algorithm that no one is ever forced to disclose. We are asked to accept as fact that someone was traveling at a certain speed or had a certain alcohol concentration in their blood. Yet the courts don't require that the folks who use these black boxes prove up their knowledge of how they actually work.

Let's think about that for a second. The Intoxilyzer measures the changes in a wavelength of light to determine the alcohol concentration of the person blowing into it. The alcohol concentration is expressed in terms of volume. Just try getting an explanation from a cop or from the state's "expert" witness as to how we translate length into volume.

I'm still trying to figure it out. In the meantime, I've got a magical yardstick I'll sell you. It'll tell me how much you weigh just by measuring how tall you are.

2 comments:

Thomas Hobbes said...

Is anyone still trying to measure wavelengths of light these days? That's a pretty dated approach . . .

Houston DWI Attorney Paul B. Kennedy, said...

That's what the Intoxilyzer 5000 does. The light bulb shines through the test chamber and the machine measures the difference in the amount of light emitted and absorbed at the end of the chamber. It then assumes that the "missing" light was absorbed by the alcohol in the test chamber. Then thought a little hocus pocus and mysterious calculations that no one can explain, the machine spits out a number that is supposed to represent the test subject's blood alcohol concentration.