Given perfect conditions, sure, then you can walk around through the dark and track the deer with flashlights, attracting attention, etc. It would be alot easier to use a 22 shot to their head and drop them where they are standing. Not much noise, can get out alot further than a crossbow with more consistency.
You could shoot your bow out to 50 yards at night as well.
While we are in speculation mode as to how this crime was pulled off, heres mine, maybe it was an NYB member trying to provide proof of their organization's claims.