Why didn't they let Susan tell Mike?

Susan is clearly struggling with the whole murder thing and wants to tell Mike and they won't let her. She's clearly a flight risk and is potentially drawing suspicious attention to herself and them all and Mike has been to prison and clearly would understand it's in self defence AND he forgave Orson so clearly wouldn't have turned Carlos in.

It makes no sense that they wouldn't try to help Susan - Mike would definitely be able to ease Susan's concerns and he wouldn't tell the police and would probably also be good at helping them if the police started to get suspish.

I'm pretty sure they do eventually tell him or he finds out (only my second time watching season 8 so can't fully remember).

Thoughts?