Get a nail gun | Day 4 - Monday: Officer Hicks, give me that ring! Randal's Monday Guide

Talk with the thief. You need to pretend you're the cop.

Go to Threepwood Station and talk with the kid, who has got cop's badge and a water gun. He wants a better gun.

Go to Randal's apartment. When Bob puts away his tape measure for a while, replace it with the gum. Take a nail gun.