The novella was based on real-life events that occurred to a family that García Márquez knew. García Márquez heard the story of a young couple that got married in Sucre and, on the day following their wedding, the groom rejected the bride due to her lack of virginity. The bride was determined to have had relations with her former boyfriend, who was consequently pursued and murdered by the bride's two brothers in order to avenge the family's honor. Though many publications speculated that García Márquez had witnessed the murder firsthand, the writer was in fact not present during the events, which took place in Sucre in 1951.
There are a few key differences in the action of the story and what took place in reality. For one, in the novella, Santiago Nasar did not have a prior relationship with Ángela Vicario before her wedding, whereas in real life, the bride was deflowered by her former boyfriend. Additionally, García Márquez chose to make the two assassins in the novella twins, Pablo and Pedro Vicario. In real life, they were simply brothers. Lastly, in the book, there is a reconciliation between Ángela and the groom who rejects her, Bayardo San Roman. In real life, there was no such reconciliation.