MELBOURNE, Australia (AP) — A suspected gunman accused of killing 15 people at Sydney’s Bondi Beach conducted “firearms training” in an area of New South Wales outside of Sydney with his father and recorded a video about their “justification” for the attack, the Australian Broadcasting Corp. reported Monday, citing police documents.

The police statement of facts was made public following Naveed Akram’s video court appearance Monday from a Sydney hospital.

The statement alleges the 24-year-old and his father, 50-year-old Sajid Akram, threw four improvised explosive devices toward at crowd involved in a Jewish event at Bondi Beach on Dec. 14, but they didn’t explode, ABC reported.

The New South Wales court media unit could not immediately provide a copy of the statement.

Police shot the father dead at the scene and wounded the son.

The son was charged last week with 59 offenses, including 15 counts of murder and one of committing a terrorist act.