I’d rather sort problems out myself in case they blame me again

I was up town clubbing in Birmingham and I came out the club with cousin and her fiancé. Then, two lads tried to rob my female cousin's bag so I chased after them, caught one of them and held him against the railing so he couldn’t go anywhere. I saw the police not too far down the street so I called for them to come over. They came over and grabbed me, pulled me to the shop window and slammed my head and body into it. They forced my head to floor and put his knee in my face and let the robber go. I felt like I was the one committing the crime, I kept shouting "Get him! Get him!", but they were too busy manhandling me and not listening to the situation.

I don’t feel confident in calling the police, I’d rather sort problems out myself just in case they blame me again.

Another time, there was a fight on the green and as I was walking through the park I saw that someone was on the floor with blood on them.  Police came and everyone was running. I was walking toward the guy on floor. The police shouted at me to stop so I stopped. They asked me what happened, I told them there was a fight and everyone had run off. They then said “I’m gonna have to search you because there was a weapon involved”. I was shocked as obviously it’s not me - the guy talking to the police telling them what happened - that had done it.  They didn’t find anything and I was confused that they thought I was involved and embarrassed.