Yes the vein is cut to speed up death. The killer or killers took double measure to make sure their victims are dead. The killing is primarily to hide something very personal and a hand of a dentist cannot be ruled our. This particular vein in very important to a dentist. To locate that particular vein, cut it, to drain out blood needs time. Killers in this particular case were not in a hurry. They have taken their time. Not just that they have collected each and every tool that could have served as evidence. If there are no finger prints, suggests the possibility of using gloves by killer/s. Gloves again suggest a doctor. It is a preplanned murder.
