Complex sentence: The detective falls to the ground, dead, as he begins to dawn, and return a few seconds before they found his body in the opening sequence of the video (after the preface reported by Cerati).
Split into simpler sentences: The detective falls to the ground, dead, as the day begins to dawn. The video returns to a few seconds before the body was found in the opening sequence of the video (after the preface reported by Cerati).