According to the Criminal Procedure Act(article 196④) and the Juvenile Act(article 4), when a police officer finds minor offenders through patrol or crime reports, he or she shall refer them directly to the public prosecutor or to the competent Juvenile Department. However, in spite of these Acts, some minor cases are closed at the police stage where the offence is not serious and the offender has made a sufficient effort to repair the damages caused by his or her behavior. Police diversion has some positive effects such as relieving the burden on the judicial system and enabling offenders to avoid criminal charges. To activate police diversion, Korean National Police Agency has recently introduced “Board of Minor Offences” and “Board of Juvenile Offences” consisted of several members including civil members. These boards examine minor offences and decide whether to issue a caution, claim summary judgment or criminal charge. This process is preferable because it can prevent police officers from dealing with minor cases arbitrarily. However, there is still some legal controversy concerning police caution and summary judgement. In this article, I examined following legal problems on dealing with minor offences in police practices. First, with respect to the authority of police cation, the police diversion is based on the principle of proportionality. Regardless of whether the case can be referred to the summary judgment process, the police has some discretion whether to divert the case or not when it is not serious crime and the perpetrator makes a reparation. Therefore, police practice guidance should be revised according to the principle of proportionality. Second, summary judgment process can be appropriate to juvenile minor cases as well. Considering that timely interventions are important to rehabilitate juveniles, it is hard to say that the summary judgement with police intervention is against the philosophy of Juvenile Act.