You can do all of that without suspending them from duty.Suspension is not some sort of punishment or negative judgement. It is a part of the standard process to make sure that the investigation is done properly, and to make sure the officer involved is not over-stressed, etc. Not madness, but a very sensible approach. The alternate approach would be "Yeah, mate, I know you just shot someone, but that is just routine, and I need you back at work at 8am tomorrow, and try not to worry about what happened today, or about being tracked down and harassed by the press and general nutters in the next few days. Oh, and the inquiry team will be giving you a call soon - try to make time during your normal working day to talk to them."
As it happens the automatic suspension rules have now been changed as promised (google).