Is it really possible for someone to merely wish to perform papa (or punya) and then proceed to do it? E.g., if one person likes to do papa, s/he can harm someone. However, the desire to ham someone should also arise. If s/he has the opportunity to harm someone or put someone in trouble but doesn't have the desire, it won't work. So, both the situation and the desire should arise.
Scripture says each and every situation is due to karma phala (karmic reward). One cannot harm another person who doesn't have that kind of papa in their account (e.g., a girl's karma account in case of a rape). If a man really has the opportunity and the desire to harm another it simply means that the karma phala of afflicted person is allowing the act of rape to happen.
Also, according to scripture, each and every enjoyment presupposes punya and by harming others or say stealing things, if one gets pleasure it must be due to his previously accumulated punya. Without punya, he cannot really enjoy the incident. So is he really committing a sin and gaining new papa or simply using up the punya already in his account?