[stusmith1977]

I vaguely remember there was some discussion of this in 'Metamagical Themas' by Douglas Hofstader. It's been a while since if I read it, but if I remember correctly he drew some parallels between law and provability in maths - basically, you can either have a system of law which cannot cover everything you want to make laws about, or you have a system of law which does, but which has some undecidable laws. Feel free to correct if I've misremembered.

[shantanubala]

You can take it a step further: until we can model human behavior mathematically, a legal system attempting to regulate that human behavior cannot be modeled in a mathematical way.

In other words, by the time we have consistent laws (in the mathematical sense), "Precrime" could already exist.

[sea6ear]

Very similar to Godel's incompleteness theorem, or perhaps an application of it.