That was 2 on one in an empty house. Lots of time. It looks to be the speed and kill efficiency plus 1 attacking 4 that makes it differentI think people are way over thinking the knife. It takes no skill to stab four people with a knife like this, just brute strength and no conscience. Field dressing animals, butchering, etc. is precise. Also, these types of knives are very common and can be purchased anywhere from online to your local sporting goods store or pawn shop. I believe the two sadistic teens who killed Cassie Jo Stoddart in what they dubbed The Scream Murders had an older friend purchase similar knives from a pawn shop to commit their crime.