Imagine two experts.
Expert one is young and arrogant. He has no practical experience. He testifies to scientific “facts” that seal a person’s fate. He grudgingly acknowledges that science is not absolute, yet he speaks in nothing but certainties when it comes to each and every fact weighing in favor of guilt. He insists that his “science” is infallible and that things must be a certain way. He uses big words to build even bigger claims.
Expert two has a half-century of practical experience, and he more or less founded his field of study. He’s conducted over fifty clinical trials involving the type of thing to which he’s testifying. He has academic and professional credentials that can’t be beat. He testifies that things are complex and that no reputable scientist would ever dare to make the ridiculous claims expert one did.
Expert one wins. Every time.
I recently talked to the jury in just such a case, and they didn’t believe a word expert two said. He wasn’t sure enough. Expert one told them what to do with authority. Expert two only gave them variables. He wouldn’t commit. The problem is the foundation of science in the courtroom itself.
By its very nature, science is fluid. Reputable practitioners gather measurable evidence and subject it to specific principles of reasoning. From that, they develop theories to test and retest. They gain knowledge, but they don’t produce “facts” beyond the empirical data of the studies themselves. They gain knowledge and produce other theories which each must then be tested and retested. Validation does not create truths, but rather principles at best. Outliers exist. They may be explained, but that process too requires more testing and analysis. When the reason for discrepancies is explained, it isn’t much more absolute than the initial hypothesis. It’s a tendency, an assumption, or at best a theory. It certainly isn’t a “fact” by any stretch of the imagination.
In the courtroom, science overcomes reasonable doubt with great ease. Modern-day concepts in forensics and toxicology with far less supporting data than now-debunked theories about phlogiston or spontaneous generation are told to juries by smart people like expert one, and juries love it. They drive cars built by science over bridges built by science to jury duty, and if they get sick and we have to use an alternate, they go to doctors who use science to diagnose and treat their problems. They trust it. Blind confidence is quite comforting.
Science is used to show that someone is in fact guilty when the reality of the situation is that science only suggests things may be a certain way. A systematic undertaking intended to develop knowledge that is anything but static is used to convince a group of non-practitioners of an absolute. The end result is a trump card in a game where lives are at stake.
Simplicity wins. Thoughtfulness loses. Science is more about questions than answers, but people inherently prefer answers to doubts. It’s hard to blame the jurors, though, as stupidity can be seductive. Easy answers ensure we’re all home for dinner. Except the defendant.