You could always do a mix of both for different crimes and stuff. Type 2 is probably the best overall but type 1 can be interesting to mix things up sometimes else it can get super repetitive. Also you can always tell part of the crime without giving everything away (like describing a murder without saying who was doing it) so the audience knows the details and is also trying to work out who it was. Mostly it would depend on the crime as I think depending on what it is depends on which way round would be more interesting. Good luck!!