Gmail account in the phone? Android Device Manager - locate your phone will give you a map of where the phone is or, if it's off, where it was last. (Move the white box if you don't see a locating pin on the map - the box may be covering it.) Keep following it for a while (On and off - before a person would have left the house in the morning. mid-morning, mid-afternoon, late in the evening, ...) and you may be able to determine where the thief lives, works or goes to school. Then go to the police with printouts of the maps.
(Since you were assaulted, if you haven't already filed a complaint with the police, you should now. Simple assault isn't much of a crime, but if you got hurt, it adds battery, and it starts getting serious. And if you got hurt at all, if they ask if you want to go to the hospital, say yes. You're a crime victim - insurance or not, you'll be treated. (Assault and battery in furtherance of theft [or armed robbery if he used any sort of weapon] means that the plea the felon will be offered is a lot stiffer than if he's just charged with stealing a cellphone that you eventually get back.)