'There is no honor amongst thieves' is a proverb for a reason. Case in point, my nephew, who got shot at point blank range (from behind, no less) by his 'best friend'. Criminals trust each other just long enough until there is a way to get ahead at the expense of the other.

Between 'calculative trust' and 'personality based trust' there are many poles (and other varieties of trust besides), on the whole you're much better of trusting a non-criminal than a criminal.