The white supremacist who slaughtered 51 worshippers at two New Zealand mosques had intended to burn down the mosques afterward, a prosecutor said in court Monday, while describing two of those praying as making heroic efforts to stop the mass shooting.

New details about the March 2019 attacks were outlined during the first day of a four-day sentencing hearing at the Christchurch High Court. The hearing gave some families and survivors their first chance to confront the gunman.