Texas is one of the few states that allows you to shoot to protect property.
Most states require that you be in fear of loss of your life or grievous injury to shoot an intruder.
Pennsylvania is that way.
Belief that the intruder intended rape, incidently, would qualify as grounds to shoot.
There are a couple of other little niceties to the law that are important to be aware of, including that you can't shoot an intruder when he/she is fleeing.
Some states require that the homeowner make all attempts to retreat before firing. (Basically you have to let the guy who wants to kill you back you into a corner before you shoot so that it's justified.)
The majority of "defensive uses of firearms" don't involve firing a shot.
And I have the crazy Texan Outgunned. (not the mildly weird one, though. I've seen pictures.)
(there is a .pdf document called
"Gun Facts" that has a lot of information about firearms and their use in the US. Defensive uses is covered on page 31.