If someone is out on work release and gets caught bringing marijuana and a knife into the prison what is he looking at ?

A knife??? If he was on work release, he must have had a short sentence. That is likely to change. He is looking at spending a good deal of time in the SHU for starters - our guess is at least several months. Then he is going to then get transferred to a much higher security facility that what he was in. The knife is a weapon and the additional charges could get ugly. The marijuana is serious, but not like getting caught smuggling a weapon into a prison.