I had the same kind of incident, although it wasn't for shoplifting, when I was 17. I did not get convicted, just arrested. I recently had an interview with an airline, and they asked me if I had ever been arrested. I told them that I had when I was 17, but not convicted. Told them the entire story. Actually was my fault, stupid kid being a stupid kid. They had me write an account of what happened for my file. I was still offered the job. Just be honest.