How old was I, when I became a suspect for life?

I'm trying to remember how old I was, when I discovered that I was "a real suspicious guy." I was 18. It was the summer of 1968, in Chicago, just before the Democratic Convention. It was late evening. My dad owned a television repair business on 63rd Street. When we closed up shop, we put the televisions we were working on in the vault and carried the repaired sets to the van out front, so we could make deliveries on the way home. That's where the trouble started. As we were getting into the van, a police car, with lights flashing, blocked us in. Two officers got out, guns drawn, and told us to get out of the van with our hands up. They were convinced we were burglars. I thought this would be straightened out immediately. The business name was "C. Ingram's Radio and Television." The Van was registered in his name, Case closed.