Death At The Door

All across the country a serial killer is at large, he is known as the Red Woodpecker. No description can be given as no one has seen him and lived to tell about it. His killings are described as this: he arrives at the victims house and neighbors have described hearing a loud knocking sound, when authorities arrive at the house, they find scratches on the door that look as if caused by a knife, once inside victims are found in a state that I am not permitted to describe, and on the wall, written in crimson blood is Knock on wood, you may be good, but limb by limb, my next victim, could be anyone.
Everyone please be careful and stay safe.
-This has been a message from the National Broadcast System, This was not a test.