Matter of Justice
Bring the document file from the police station.
1500, Pride Gun Mod
After returning from the main quest “Lady in Trouble”, return to the church and talk to Tim. After receiving the quest, I suggest fast traveling back to the Abandoned House – Square (Nick's Hub) so you can receive another quest in the police station as well. Travel back to the church and follow the trail to the police station. Once inside, continue to the second floor and head to the prison cell where you found the ID earlier. Talk to the radio to update the quest “Paperwork”.
Continue following the trail and fight your way through the undead until you reach the last office room where you found Jin earlier. Tim's File is located in the same corner cubicles where you found the ID earlier. The door in the other side of the room should be open now. Go there and find the Shotgun Ammo blueprint inside. Return to Tim to complete the quest.