Back in the 1990s, we learned a lot about the serious physical harm that can result if a baby is shaken. While it was probably intuitively obvious to everyone, forever, that violently shaking an infant puts them at great risk of serious injury, a few high-profile cases brought the issue to the forefront. There’s absolutely no doubt that shaking a small child can easily cause serious, sometimes even fatal, injuries.
Now, however, new scientific evidence (longer article here) suggests that some of the testimony used in criminal cases to convict people of child abuse in shaken baby cases may not be as reliable as once thought, and courts may have to re-examine some of their past convictions, to the point that some experts are suggesting that innocent people might have been convicted of crimes they did not commit.
Basically, it’s looking like the internal brain and eye injuries characteristic of the whiplash-like action that shaking induces (which leave few, if any, external signs) have other causes which are more common than once thought. I should stress that this new information doesn’t even suggest that shaking a small child is less dangerous than previously thought; it’s still a recipe for disaster. It just suggests that other somewhat-common accidents can cause similar injuries, and should be considered and thoroughly investigated before a parent is charged with child abuse.
However, whenever evidence like this comes out, we have to face the extremely uncomfortable proposition of re-investigating what were thought to be open-and-shut cases, knowing full well that we may find out that innocent people have been convicted.
Several branches of the Innocence Project, which have long championed the use of DNA evidence to exonerate people wrongfully convicted of crimes, including some people on death row, have turned their attention to shaken baby cases, and this new scientific evidence, particularly in cases involving parents and nannies who had, up to the incidents in question, been model caretakers with no history of abuse or neglect.
While revelations like this are certainly upsetting, that should never stop us from re-investigating criminal cases when new evidence becomes available.
After all, our criminal justice system is predicated on the notion that everyone should be presumed innocent until proven guilty, and if the prosecution fails to prove someone’s guilt beyond a reasonable doubt, they must go free, even if everyone agrees that they’re “probably” guilty. This necessarily means that, sometimes, a guilty person will go free. But, that’s the price we, as a society, have chosen to pay in exchange for the knowledge that (at least in theory) it’s extremely unlikely that an innocent person will be convicted and imprisoned.
However, as we’ve seen in other criminal cases, especially when DNA evidence is involved, the justice system values finality almost as much as it values fairness. So, courts are often reluctant to re-open cases where the defendant has been convicted, and exhausted all appeals. At that point, after all, the whole thing is supposed to be finished. But ultimately, everyone recognizes that re-opening these cases, especially when they result in exonerations, is the right thing to do.
Another unsettling element of this story is the fact that many physicians who have built their careers studying and treating injuries characteristic of shaken children have also turned their services as expert witnesses into extremely lucrative side careers. One aspect of the legal system that surprises many people who don’t work in it is the vast amounts of money that expert witnesses can charge for their services.
Intuitively, the idea that a witness in a court of law can charge money for his or her testimony seems ridiculous. And most witnesses cannot (though they can be reimbursed for any expenses the incurred in testifying, such as fuel costs and the like). Expert witnesses, however, can charge thousands of dollars per hour, on the grounds that they usually have to conduct a lot of research and possibly experimentation in preparation for their testimony. In an effort to avoid ethical problems, the fee an expert charges cannot be contingent on the outcome of the case. Nonetheless, there are still concerns that expert witnesses, being paid by the party that’s calling them, might have some incentive to skew the data in favor of their clients. That doesn’t mean that the services of expert witnesses aren’t essential, of course.
But it’s important to remain critical when examining their testimony, and always being open to the possibility that the scientific consensus might change, and that new evidence casting doubt on the outcome of an old case might become available.