If you're a drug dealer with a federal agent pointing his gun at you and your stopped car, don't start driving your car towards the agent. You will get shot. And even suckers like me won't have any sympathy. See Robinson v. Arrugueta, No. 04-10856 (11th Cir. July 7, 2005).
However, Robinson also indicates that the law of excessive force is moving in a dangerous direction. In Brosseau v. Haugen, 125 S.Ct. 597 (2004), the Supreme Court suggested that a car might be a deadly weapon. In Robinson, the Eleventh Circuit (though looking to state law) held that a car was a deadly weapon. One implication of this holding is that a police officer can use deadly force every time a person flees via car. As I blogged in March:
A jury can't kill you unless your guilt is proved beyond a reasonable doubt. But a police officer - whom we can't burden by requiring him to know the law, see Devenpeck - can kill you based on probable cause. The Court's technical holding was that a "reasonable officer" would not have known that shooting someone in the back - instead of, say, shooting the tire out - as he's sitting in his car was excessive force.
Granted, if the guy in Haugen was going to harm a child, I'd rather see him stopped quickly. But I also don't sanction summary executions, which is what an on-the-street shooting is. The Court should have required a bit more quantum of proof that the suspect was really dangerous instead of giving officers a blank check to open fire.
Certainly, we would not object to a police officer's shooting someone speeding through a school zone. But given the way qualified immunity doctrine evolves, a few more people who present no harm to anyone will be shot, and a few police officers will escape liability, before this question, "When can you kill a fleeing motorist?" is answered. The problem with qualified immunity is that it encourages police officers to cross the line separating lawful from unlawful conduct. Which sometimes means, the line between life and death.