María del Pilar Pérez López (born 21 December 1951) is a Chilean architect currently imprisoned for the triple murder of her husband, fellow architect Francisco Zamorano Marfull, his at-the-time boyfriend, technological medic Héctor Arévalo Olivero, and her nephew-in-law Diego Schmidt-Hebbel Niehaus, between April and November 2008, all committed through the use of hitman José Ruz Rodríguez.
[6] Pérez's family has described Pilar as a troubled and violent woman, and her mother testified that she joked about the number of hit men in United States after a trip to New York.
[8] On 23 July 2008, José Ruz shot and killed the couple made up of Francisco Zamorano Marfull and Héctor Rodrigo Arévalo Olivero.
[9] On 23 November, he tried to carry out this plan, but only managed to shoot Diego Schmidt-Hebbel Niehaus, the boyfriend of Belén Molina, Pérez López's niece, before being found by the rest of the family and escaping from them.
After being arrested, Pérez had a suicide attempt and sent a letter to her daughter, asking her to offer Ruz money in exchange for modifying her version of the events that occurred to incriminate her brother-in-law Agustín Molina.