Find out who cut the whore

Find out who cut the whore is the third task you get from Earl Marion. You start by going to the Malamute Saloon to question the bartender, and he shows you a Morningstar Mine scrip. When you go to the Morningstar Mine and ask around, Obidiah Hakeswill will confess right away. From there you can kill him, and you will receive $500 from Marion, but no quest xp. If you let him go you receive no experience or money from the sheriff. The best option would be to take him into custody where you receive 1250 xp and $500.