Kenneth Francis Harrison (September 4, 1938 – April 20, 1989), known as The Giggler, was an American serial killer who killed four people in Boston, Massachusetts from 1967 to 1969, for which he was sentenced to life imprisonment. He earned his nickname from calling the authorities after each killing, professing it was the killer speaking and uncontrollably giggling before hanging up. Harrison died in hospital in 1989, following a deliberate attempt to commit suicide by overdosing on medication.