Lizzy Borden, not by definition a serial killer, but a notorious killer nonetheless. One day as her father was napping on the living room sofa Lizzy Borden took an axe and hit her father's head with it repeatedly some where around 40 times, completely disfiguring his face into an unrecognizable mess of blood and gore. Almost immediately after Lizzy attacked her mother in her bedroom, again hitting her head with an axe over 40 times.
Lizzie Borden took an axe,
And gave her father forty whacks.
And when she saw what she had done,
She gave her mother forty-one.
kill count: 2