Public� opinion� about� seriousness� of� crime� was influenced� by� much� internal� from� person� (observer)� variable, beside variable form nature of crime and criminal profile. One of internal variable is value which in embracing by individual, one of the� values� is� coming� from� religion� value.� In� religion� values, especially Islamic value, arranges people behavior in relating with his god and with other people. This religion value also influences their� opnion� to� crime� and� action� as� response� to� crime. Nevertheless� has� not� many� field� studies� yet� publication explaining� about� the� Islam� value� in� criminal� justice� system phenomenon� and� influence� at� people� behavior,� so� that� it generates� many� questions� about� how� Muslim�s� opinion� crime and� criminal� justice� system.� The� purpose� of� the� research is� to know� crimes� was� assumed� is� serious� for� Muslim� and� Muslim�s consideration� are� in� determining� seriousness� of� crime.� There search involves 163 psychology undergraduate. In the research, respondent� asked� to� choose� out� of� 23� form� of� crime� assumed most� serious� and� followed� with� open-end� questionnaire� related to� reason� of� election� of� crime� that� is� most� serious.� The result shows that apostates (murtad), intended genocide and corruption are� most� serious� crime.� Goodness� and� humanity� value� is� most dominant� reason� in� determination� of seriousness� of� crime. Opinion� about� seriousness� crime� has� implication� at assessment of justice at Law enforcement.