Can the courts still take it upon themselves to charge me if I recently took a wallet and returned to the owner?

The right to bring charges does not belong to the victim. It belongs to the prosecutor (or the attorney general). The courts do not decide whether to charge you. If a felony is charged, the courts may review the prosecutor's evidence to see if it is sufficient to go to trial, but otherwise will not decide whether to charge you. Many prosecutors will go by the wishes of the victim not to press charges, but some will not. You potentially face a felony charge of larceny in a building, or misdemeanor charges. If you are charged, you will need representation. Avoid making any further statements about the case to anyone but your attorney.