Lawsuit -- Write With (AP) Style

In AP style, under titles:

In general, confine capitalization to formal titles used directly before an individual's name.

That means, if you are referring to the principal in the generic, then it's lower-case:

In response, the principal said the plaintiff's son is a dumbass.

If you are adding the title before the name, then you do capitalize:

In response, Principal Greg Hubbard said the plaintiff's son is a dumbass.

But if you do not directly connect the name and title, then the title remains lower-case.

In response, the principal of the school, Greg Hubbard, said the plaintiff's son is a dumbass.

Please review AP Style under titles.