What can happen if a 17 year old pleads guilty of stealing?

In the eyes of the court, you are an adult. So if you plead guilty, you will end up with a conviction for stealing on your permanent criminal record. That conviction can not be removed from your criminal record later, and it will prevent you from getting a job, renting an apartment, and getting federal student loans for school. Maximum penalty in Missouri for misdemeanor (under $500) stealing is 1 year in jail and a $1,000 fine. I suggest that you hire an attorney to represent you if you want to avoid having a conviction for stealing. Your attorney can get the charge dismissed or reduced to a lesser offense, such as "Littering."