Complex sentence: The murders started in the afternoon of 4 December 1986 in the apartment of one of Delgado's English students, where he stabbed to death his 15 year old pupil Claudia Rincón and her mother, Nora Becerra de Rincón.
Split into simpler sentences: The murders started in the afternoon of 4 December 1986 in the apartment of one of Delgado's English students. There he stabbed to death his 15 year old pupil Claudia Rincón and her mother, Nora Becerra de Rincón.