If a Game Master is currently roleplaying a City Guard and available to trace this IC case of crime, he may roleplay to interrogate both parties, I believe... - Nevertheless, he would have to solve an OOC case with priority.
I remember that such a case recently happened where a notorious player's character got reported for challenging and killing newcomers right at the plaza, which is IC a crime (especially in a combat-free area like the plaza) and OOC a harrassment at once.
