Pain as According

Note: If the spell is cast by someone with a negative karma/aura, the spell may backfire due to believed duplicity to whomever you're casting the spell on

Hold the buttercup flower and with it cupped in your hands with the cloth laid over your cupped hands say from 1-5x (depending on how strongly you feel that the person has negative karma/aura):

"I wish pain upon thee,
thou does indeed house an evil soul.
Exceeded limit,
poison poison poison.
Grant my wish true,
of death from thy beauty.
Ingest harmless memories,
tainted with sin.
Bleed out from in,
sin by sin.
Memories made evil,
like your soul it holds no more truth.
Ingest thy own sin.
Die if I know true."

After that, the flower has the power to harm or kill anyone with negative karma/aura. All you would have to do is get the person to ingest it, and let the spell decide their fate. If the spell doesn't work contact me if you still believe the person should be punished, otherwise the person was simply not needing punishment.