I've never believed she was kidnapped. I'm more inclined to think that she just panicked and ran, with him.
But my gut feeling is that she did not plan for her parents to be murdered.
Could be wrong, of course.
I'd be willing to bet that innocent or guilty, she spends the rest of her life doped up. It's all such a sad waste, all the way around.
Looks like part of lover boy's defense is that Kara is no victim.