Is the dume spell the right move?

I recently had a friend who was killed brutally two months ago by a group of guys and I was wondering if the dune spell is the right move. I know the guy that they caught and the manager of a nightclub who initiated it. The way they murdered him was so senseless and cruel I couldn’t believe humans can be so horrible. Throughout the beating they showed no mercy and left him on the road humiliated him by removing his clothes while he was laid out there and he eventually was hit by a car while unconscious. I waited to see if the detectives would do their jobs however the guy that they charged only got involuntary manslaughter and the driver who ran him over got out scotch free and the manager as well, not to mention the manager is a person who loves laughing is wealth and cars and he shows no remorse on what he did. I was so mad that I hired a person to place a hex on the yesterday and the person advised the dume spell would be the best bet, so I at first I paid for it but now I’m having second thoughts because I don’t know if that’s going too far but the way he was killed keeps replaying in my mind and it hurts me deeply. I also placed the same hex on the woman he went to see because throughout the investigation she painted him as the bad guy and lied about him being a drug addict and he was super aggressive and pretty much influenced the detectives to view him negatively to start. So what should I do and what spell should work for this case