Except based on what has been reported, DNA samples from those people frequenting the Sherman house was not taken by LE for many months after the murders, so who knows what DNA LE collected at the crime scene.Any DNA from somebody who was known to frequent 50 Old Colony (Family; staff; RE agents) would be irrelevant. Any 'strangers' likely would have taken precautions such as gloves, masks, booties, even painter-type suits.