• New Zealand grappled with grief and horror on Sunday, two days after a gunman opened fire at two mosques in the city of Christchurch , killing at least 50 people. The terrorist attack appeared to have been carried out by a white nationalist who posted a racist manifesto online and streamed live video of the killings on Facebook. • Prime Minister Jacinda Ardern said on Sunday that the suspect, an Australian, would be tried in New Zealand, and that her government would discuss gun regulation at a meeting on Monday. “There will be changes to our gun laws,” she said. • Minutes before the shooting began on Friday, Ms. Ardern was emailed a copy of the manifesto purported to be from the gunman, her office said. Many news outlets and lawmakers also received the email. • The family of the suspect, identified in court papers as Brenton Harrison Tarrant , 28, has apologized for the attack. In an interview published online on Sunday by Australia’s 9News , his grandmother said the family was “shattered” and denounced his actions as “unrepairable.” Suspect will be tried in New Zealand, prime minister says Prime Minister Jacinda Ardern said Sunday that the suspect…