I will have to teach them to be cautious around police, to make no sudden movements, to act as if they are under suspicion at all times.

I'm not going to face this decision myself, so take what I say with a grain of salt. But do you really want to teach your children that they must be suspicious and wary of white people? Because it's either that or teach them that the reason they have to be careful is that there's something wrong with them.

I don't doubt that they will someday encounter someone like the client your wife just had recently. But it seems that raising them to expect it will cause them to see it even when it's not there.

I'm really sorry that you, or anyone for that matter, have to make this kind of decision. Still, I hope you can figure out a way to teach them that some people won't like them because of how they look, but that those people are the exception rather than the rule.