PRETORIA, South Africa (AP) — A ballistics expert testified Friday for the defense at the murder trial of Oscar Pistorius, saying his analysis of the scene where the Olympic athlete shot Reeva Steenkamp differs in some ways from the reconstruction of the shooting by police investigators.

The study of the sequence and trajectory of bullets that struck Steenkamp through a closed toilet door is at the center of testimony over her body position at the time of the shooting, and also relates to the defense’s contention that police investigators made mistakes.