This is my life

Dear diary,

You don't normally find out that the fish and chip shop down the road sells fish from the river Thames. I didn't know that there were any fish alive in there. But today was surprising for another reason.
I was walking to the library to get out some books as usual when I noticed it was closed.
I eyed the librarian walking into Clothes R Us shop and remembered that she always shopped at the tailor's instead of there and so I knew that something was wrong. I followed her looking casual so no-one would know I was spying on somebody. I entered the store but I couldn't see her anywhere so wandered around keeping my eye out then I remembered the only other place I hadn't looked was the changing rooms. I walked over there and peeked through a crack in the door. I didn't see the librarian, but someone else. I was about to quickly avert my eyes, except that I was shocked by what I saw. I couldn't tell whether it was a boy or girl so I am gonna stick with boy for two reasons. The first is I don't like spying on girls getting changed because I end up seeing stuff I probably shouldn't see. The second was that he had short hair which most boys my age seem to have. He slipped his hand into his bag and pulled out a wad of wallets. My mouth dropped open. He was a pick-pocket! I grabbed my backpack off my shoulders and checked if my wallet was safe. Sure enough it was. I ducked out of earshot, pulled my phone out of my pocket, and starting dialing the police when I notice the guy slip out of the changing room.