Check out your dollar stores they always have cop and robber stuff for the kids like little badges, handcuffs etc. Maybe make a black and white stripe shirt to make your Mom look like a jailbird. You could use black licorice on a cake to look like cell bars. My sister works for the sheriffs dept and so does her fiance they are getting married next year and she (a cake decorator in her spare time) is making the grooms cake like their squad cars. Hope you have fun!