I put my friend in jail for robbery, but how do I drop charges because they do have undiagnosed mental issues?

I put my friend in jail because they stole $100 from me by force and kicked me out of their house. I think they MAY would have returned it at some point. They refused to give it back for that day though. I did not know the cops would charge with Class C felony robbery though. They are on assisted housing because they do suffer from depression but I don’t think it is clinically diagnosed. If I give the District Attorney my viewpoint and since they have no criminal record is it likely they won’t go to jail for a long time?