That's discouraging...Do you have an academic advisor at school who you could talk to? How recent were your criminal charges? I see you're in Canada, so I'm not sure how criminal stuff works there. I know in the US at least the petty theft would be a misdemeanor, and jobs tend to ask about felonies rather than misdemeanors. For the hit and run, I assume it depends on the circumstances, like if anyone was injured, etc. (I have a DWI on my record--got pulled over, didn't hit anyone or anything--but I got probation before judgement and went through probation without problems, so I haven't formally been convicted of a crime).

But I'd see if there's someone in your program that you could talk to. Or maybe your university's career center.