On the afternoon of April 1, 1965, state troopers visited the Duncannon home of 47-year-old Byron Halter and his family, consisting of his wife, Betty, their 17-year-daughter, Holly, and Betty's mother, Mrs. Elizabeth Swank, who lived in the adjoining side of the duplex. The reason for their visit was because someone had sent anonymous letters to local papers warning that four people were about to die. But this was not a cruel April Fool's prank-- it was a senseless slaughter carried out by a disturbed Sunday School teacher.