Usually the detective was making the game lively on day 1, but this time the D either isn't here (Katie?) or investigated a C. Or maybe he's here but still thinking who to investigate.
IF the D hasn't investigated and finds a G when he investigates, He/She must tell us about the investigation. Remember that the Gs will know who did you investigate so no reason to hide if you investigated a G.
If you investigate a C then don't make it public, at least not until your life is in danger. Do not contact the C either if it's not a special role, since that C can be recruited.
The D should try to find the bodyguard and work with him. But do not try to find him via PMs because a Gangster might trick you into revealing your role and then the Gs can whack you.
What I said is general knowledge for the regular players, but we have newbies and it was good to teach them how it is supposed to be played in case a newbie is the detective.