After stealing Salazar Slytherin’s locket from Hepzibah Smith, Tom Riddle uses the murder of “a Muggle tramp” to turn the locket into a Horcrux with part of his soul inside (BLC).
Tom Riddle murders a Muggle tramp and creates the Locket Horcrux
Date circa 1957
Certainty Inferred from canon
Location in Canon BLC
Type of Event Array