I Found My Rifle That Was Stolen 3 Years Ago At A Pawn Shop

I was going by a pawn shop to get a new velt sander and I saw my old hi point carbine on the display, i knew it was mine because I had a custom stock on it and I also replaced the retention pins with bolts because the pins kept shifting the aim over time, i asked them to run the serial.number just to make sure and they refused to, i called the police department and they came down and ran the serial numbers and it turns out that it is my rifle. It is now on hold at the pawn shop since there were no detectives available, im not sure what else i need to do or how long until I get my rifle back. Are there any steps i could tale to help speed up the process?