Earlier quoted context omitted.
It would be interesting to know if this is a common experience among sociopaths. I had always thought that behaviors like theft resulted more simply from the lack of empathy (and desire for the stolen item), rather than resolving some kind of internal tension.
Yes. She says "I was sorry I had to steal to stop fantasizing about violence" - it seems there is something else going on here, not just being a sociopath.
In this case, do something minor (stealing) to scratch the itch that, if left unscratched for long enough, could result in doing something major (violence).
It feels like a reaction to societal rules that don't make sense in their experience of the world, and so maybe the itch exists because the rule(s) seem irrational and arbitrary to them.
Or maybe the lack of empathy leaves a hole to be filled with mischief.