“We don’t know how much force is necessary to damage or injure the brain.”—Dr. Robert Block
Doctors, testifying under oath, are routinely permitted to speculate about the amount of force a defendant generated in order to cause the medical findings in the child.
A PICU doctor testified, “We’re talking forces you would see in a high-speed motor vehicle accident. When a person shakes a baby, the baby undergoes the same amount of force of gravity that a fighter pilot or an astronaut experiences. At 9Gs, humans need special equipment or the heart cannot pump blood into the brain. If I violently shook a baby, then the head is experiencing 10 Gs of force. If I shake a baby then hit it on an object, the head experiences 300 Gs.”
A prosecutor in a separate case argued: “The amount of force makes it clear that [the babysitter] knew what she was doing. The fact that she had a cast on her arm when [the baby] was injured is insignificant.”
We have collected hundreds of examples of testimony estimating the force required to cause the “constellation” of medical findings that prompt doctors to infer a history of violent shaking. Biomechanical research shows that humans are incapable of generating such forces. Jurors who hear such unsubstantiated estimates from an expert witness easily infer murderous intent to maim or kill the child.
Here are a few additional force estimates offered by expert witnesses. We have collected hundreds of similar statements.
| 50 mph crash or a 5-story fall |
| Fall of 2 stories onto concrete |
| Average adult being rattled back and forth by a 1,000 lb. gorilla |
| Ejection from motor vehicle going 60 mph |
| Someone hitting the top of his head with a baseball bat |
| 3-4 story fall |
| Like throwing the child out of a fourth-story window |
| 40-50 mph crash or 50-story fall |
| High-speed crash or 10 story fall |
| High-speed, 40-lb TV falling onto the baby’s head, 30 foot fall |
| 50 Gs, 50 times the force of gravity |
| 60 mph car crash without a seatbelt, ejected and impacting a brick wall |
| Like an elephant jumping into the crib |
| Being dragged by a horse, stepped on by a horse, or unrestrained in a car accident |
| 60 mph car crash or 2-story fall |
| Massive crush like head being run over by a car |
In 2001, the Colorado Court of Appeals pushed back against such testimony, writing:
The announced purpose of the testimony concerning observed accident scenarios that are known to have caused subdural hematomas in children was to establish that the force necessary to cause a subdural hematoma was such that defendant must have acted “knowingly” rather than “negligently” or “recklessly.” For that purpose, the evidence was irrelevant, highly prejudicial, and, in addition, was likely to confuse or mislead the jury.
As presented and argued, the evidence was not probative of the force necessary to cause a subdural hematoma. Put another way, to determine how much force defendant must have inflicted on the baby, it is the minimum force, however characterized, necessary to inflict a subdural hematoma in a child that is relevant. The testimony of the pediatrician of observed accident scenarios that are known to have caused subdural hematomas in children did not shed any light on that issue.
The lack of relevance, considering the purpose for which the evidence was offered, is demonstrated by the following syllogism, which is implicit in the pediatrician’s testimony and the prosecutor’s argument:
- Some children who suffer subdural hematomas are children who have been subjected to trauma or force such as that sustained by a fall from a multistory building or being unrestrained in a high-speed automobile accident.
- This child sustained a subdural hematoma.
- Therefore, this child was subjected to trauma or force equal to or exceeding that caused by a fall from a multistory building or being unrestrained in a high-speed automobile accident.
Child advocates immediately protested the opinion, saying it would hamper prosecutors’ ability to win convictions and protect children. The ruling was appealed to the Colorado Supreme Court, which unanimously reversed two years later, saying it was the responsibility of defense lawyers to be more vigilant in cross-examining experts proffering such testimony. Prosecutors called the Supreme Court ruling “an enormous victory.” To this day, experts are allowed to opine on forces, despite an utter lack of scientific support for their estimates.
It is one thing clearly to state that a certain quantum of force is necessary to produce a subdural hematoma; it is quite another to use examples of obviously extreme forces and violence that have been demonstrated to have caused subdural hematomas and then suggest that they constitute the minimum force necessary to cause such an injury in any particular case. In our view, reasonable inferences as to the underlying issue cannot be drawn from that testimony.