Approximately 8 months ago I submitted to a CIA polygraph examination for the DO. During the post-test interview, the examiner accused me of lying about the crime question.  She emphasized "serious" crime to mean something really serious, eg rape, murder, etc. and then proceeded to grill me about anything I'd ever stolen in my life, no matter how small.  I admitted to having taken some small items (greeting cards) totaling approx. $20-$40 from my high school retail job under pressure from friends/coworkers. Since then, I have been worried that CIA could possibly report my admission to local police and that I could be prosecuted. 
Points: 
1. I would have been a minor at time of crime; am 23 now. This would have been 5-7 years ago. 
2. Former employer never brought anything to my attention, we parted on good terms. 
3. During exam, I admitted to the theft, but no details, eg exactly what was taken, or any dates/times (couldn't remember anyway). 

Could I actually be prosecuted for this? How? Would CIA report me to my [former] local PD? 

The whole polygraph experience was so unpleasant, I withdrew my application.  My personnel officer seemed genuinely sorry and asked me several times if she could do anything to change my mind.  They sent me a letter telling me I could call them back and they would reconsider my application at any time.

Now, I work for another agency and hold a Secret clearance.  Anything to worry about?
Thanks for replies.