Officers are NOT trained to "shoot out tires" We are specifically told to never, ever try and shoot out someones tires. There's two major reasons why.
A) discharging our firearm is permitted only to control a "deadly force threat" (imminent danger of death or serious bodily injury to ourselves or others). If we shoot at someone, it better be because we reasonably believe that the subject WILL kill/hurt someone if we fail to act. We are trained to shoot until the threat is controlled. For us, that typically means shooting at a person's center of mass. why? You ask? Because center of mass is the largest target, meaning we are more likely to score a hit and most likely to stop that subjects deadly force threat the quickest. We cannot "shoot to wound",because, a wounded subject is still capable of killing or harming you or someone else. Shooting to wound is using "pain compliance" to establish control....but we are using a lethal force control option. WE are using a level of force that is likely to cause death or serious bodily injury, to address a threat that we feel can be managed through non-lethal means. The very act of using a firearm to "wound", negates your justification for using that level of force. We use lethal force to "stop" a deadly force threat. We are trained to stop the threat in the quickest, most effective, means.
B) we are responsible for every bullet that leaves our firearms. This includes richochets. If we're shooting at someone to "stop" their deadly force threat, and a bullet misses and injures a bystander, we are only responsible for the failure to make sure all our shots hit the correct target (whether that is because of a lack of range training, or improper equipment, whatever). Referencing my first point, if we shoot to "injure" their car....well we aren't stopping the threat. A flat tire doesn't stop a car, it doesn't make the driver less capable of getting out and opening fire. We would be using lethal force to control a resistance that we de facto aknowledge can be met with less lethal control. So NOW, that stray bullet or that richochet, has injured or killed an innocent bystander...when we had NO justification for using it in the first place. That's why we have things like tire strips..or tazers. Those are ways for us to flatten tires...or stop a threat, that are not "lethal force". Our failure to have access to less lethal control options is not justification for excessive force.