Recently, violent offending with unspecified motives toward strangers, so called ‘do-not-ask-crime’, has been rising in Korea and it has received consistent attention from the Media due to public’s fear of being likelihood to be randomly victimized by its offender. Clear conceptualization of such crime was not established yet, nor the characteristics of offenders who commit it and the necessary social policies in criminal justice system as prevention strategies. Therefore, the purpose of this research was to conceptually define ‘do-not-ask-crime' and examine main characteristics of offenders who commit such crimes. We analyzed the reports of criminal investigation for the do-not-ask-crime cases that occurred in 2012 in Korea. We found that do-not-ask-crime offenders were low in socioeconomic status and 75% of them were recidivists, most of which had a history of being convicted of violent offending toward people including strangers. We also attempted to divide them into subtypes through SSA analysis and found that they were categorized by anger, complaint, and mental disorder types. Implications for criminal justice system were also explained.