If you apply logic to any suicide that takes place using a firearm,
A shot to the side of the head, in the mouth, or to the front of the chest is usually suicide. Wounds located anywhere else are most likely homicide.
Most suicide shots are contact shots, Anything further away is likely homicide.
Number of shots fired: After one shot, even if a suicide victim isn't dead, he would likely be unconscious or physically unable to fire a second time. Multiple shots usually indicate homicide.
Returning a silencer back to a cupboard after shooting one self usually indicates homicide?