Complex sentence: The House of Death refers to a serial killing site in Ciudad Juarez, Mexico where executions were committed by members of the Juárez Cartel, some with the knowledge and participation of a United States agent ("Lalo") who had infiltrated the cartel.
Split into simpler sentences: The House of Death refers to a serial killing site in Ciudad Juarez, Mexico. The executions were committed by members of the Juárez Cartel with the knowledge and participation of a United States agent ("Lalo") who had infiltrated the cartel.