Jonathan Melendez, a keyboardist for the band Camilo Séptimo, was killed along with his pregnant wife, their three-year-old daughter, a domestic worker, and a pet. ^[1] Sebastian N was detained as the presumed responsible party for the mass murder that occurred when he arrived at the victims' department. ^[2] Security video captured Sebastian N arriving at the apartment building in Atizapán, State of Mexico, where a mass murder occurred. ^[3] On September 2, 2026, security camera footage from an elevator in Atizapán, State of Mexico, showed the capture of Sebastian N, the suspected multihomicide of musician Jonathan Melendez and his family. ^[4] Initial investigations indicate the detained suspect was a business partner of Jonathan Melendez and a friend of his family. ^[5] Authorities have detained the suspect and are continuing investigations to determine the specific motive and establish full responsibility for the crime. ^[6] Initial investigations indicated that the suspect was a business partner and acquaintance of Jonathan Melendez, which allowed him to enter the residential area and the victim's home. ^[7] Social media followers identified Sebastian N as a person of Argentine nationality accused in a July 21, 2026, Facebook post of defrauding clients of approximately one million pesos through vacation rentals in Valle de Bravo. ^[8]