Voodoo Science

If the shoe fits...

If the shoe fits…


I’m just a plainspoken Colorado criminal defense lawyer, but the way I see it…

Remember those ugly-ass size twelve Bruno Magli shoes the prosecution tried to prove O.J. Simpson wore while killing his ex-wife? That and other evidence the prosecution bungled didn’t work then, and according to a federal government report it shouldn’t work now.

The President’s Council of Advisors on Science and Technology (PCAST) has informed the chief executive officer of the United States that shoe-print, hair, ballistics, bite mark, fingerprints, and even DNA evidence are nowhere near as conclusive as prosecutors routinely pretend they are.

And the message to judges is to stop letting them get away with it.

Problems were not only with the reliability of the scientific methods used to rule in, or out, a suspect, but with how the evidence is interpreted by government experts willing to shade findings far beyond their scientific justification, in the interests of convicting defendants.

Experts love to testify — and prosecutors love to hear it, whether they believe it themselves or not — that their conclusions are one hundred percent, or essentially one hundred percent, certain, or at least certain “to a reasonable degree of scientific certainty” (my personal favorite). They like to say their error rates are zero, essentially zero, or negligible. The fact that there is no such thing as a zero error rate doesn’t seem to bother the government experts a smidge.

The FBI, to its credit, began to wonder a few years ago about its own experts. Reviewing the expert testimony in three thousand cases involving hair comparisons, the agency last year reported the science used to convict ninety-five percent of the defendants was either flat-out wrong or grossly overstated by the experts. Starting this year, they’re looking at some of the other dubious methods they’re using to lock citizens behind bars.

Based on its findings, PCAST recommends that judges never permit prosecution experts to claim that error rates are “zero,” “vanishingly small,” “essentially zero,” “negligible,” “minimal,” or “microscopic,” or to state that their conclusions are offered with “100 percent certainty” or proof “to a reasonable degree of scientific certainty;” identification “to the exclusion of all other sources;” or a chance of error so remote as to be a “practical impossibility.”

And it’s up to us ugly-ass criminal defense lawyers to hold the judges to it.


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