I murdered my music teacher

I was in a music class and we were going to have a music test and then we had a normal music lesson where we were told to dance and I decided not to dance. I noticed a camera on the big screens that had the dance moves and I was scared of being caught. Then the music teacher, that was going to give us the test answers, was going to take us on a music trip. So of course, I gave all his students poison and then murdered him by putting him in a bath and slitting his wrists so it looked like he killed his students and committed suicide. The investigators found a piece of paper that said “pop, and let us breath” so they popped the music teachers stomach and all the air came out showing something that proved I was guilty.