If Jason was 17 or younger at the time of the crime, I would sentence him to probation. The criteria in my state would not allow me to sentence him to probation if he was over 18 at the time of the crime. If Jason was 18 or older at the time of the crime, I would probably sentence him to prison for 5-15 years. I would consider a longer time if there were aggravating circumstances (such as a weapon used in the commission of the crime).
If Jason is sentenced to prison, he should be sentenced as a Youthful Offender and be released after serving approximately 10% of his sentence (i.e., 2 years). His sentence should then be suspended and he should be placed on probation with specific conditions. Because Jason was not armed and did not have any interaction with anyone inside the store, I would impose a condition that Jason participate in counseling. If Jason participates in counseling and commits no additional crimes, his sentence will not actually be served (he will only be on probation). My decision to order counseling for Jason is based on the evidence presented at sentencing. The prosecution showed that Jason had committed one offense prior to this most recent crime—stealing a cell phone from another student in high school—and successfully completed diversion for that offense.