Expelled student Nikolas Cruz was 18 when he legally purchased the AR-15 rifle he used to kill 14 students and three staff members at Marjory Stoneman Douglas High School on Valentine’s Day 2018. It is the deadliest shooting to go to trial in US history. Nine other gunmen who killed at least 17 people died during or shortly after their shootings, either by suicide or by police fire. The suspect in the 2019 shooting death of 23 people at a Walmart in El Paso, Texas, is awaiting trial. Three days before the massacre at Marjory Stoneman, Cruz made a video. To this he said: “Hi, my name is Nick. I will be the next school shooter of 2018. ”My goal is at least 20 people… It’s going to be a big event, and when you see me on the news, you’ll know who I am. “You’re all going to die. Oh yeah, I can’t wait.” Image: A school in mourning – Students at Marjory Stoneman Douglas days after the deadly attack Last October, Cruz pleaded guilty to premeditated murder, and this week the “penalty phase” of his trial begins. Jurors will decide whether he will be sentenced to life in prison or face the death penalty. Image: Campaigners organized petitions to push for the death penalty Read more: Walmart agrees to limit gun sales after Parkland shooting More than 700 people have been killed in the US since the Texas school shooting Image: The killings led to a National School Walkout in the US in support of greater gun control In his opening statement, District Attorney Mike Sachs emphasized Cruz’s brutality as he stalked a three-story classroom building and fired his AR-15 semiautomatic rifle into hallways and classrooms. Cruz, he said, sometimes returned to already injured victims and killed them with a second volley of gunfire. Cruz was “cold, calculated, manipulative and deadly,” he added. The families of the victims attended the Broward County Courthouse in Fort Lauderdale for the hearing. Some shook their heads, others wept. Image: Families attend ‘sentence hearing’ Cruz broke down during much of Mr. Sachs’s statement. The court said Cruz had a history of mental health and behavioral problems at the time of the shooting. He had said at the time of his guilty plea that he was very sorry and asked to be given a chance to help others. The jury must be unanimous to recommend that Cruz be executed. If any of the 12 jurors object, Cruz will be sentenced to life in prison without parole. Use Chrome browser for more accessible video player 0:33 “This can happen anywhere – it has to stop” Gun violence in the US has been the focus of global attention following recent mass shootings, including one at an Independence Day parade outside Chicago that killed seven people and another in May at a school in Uvalde, Texas, where 19 children and two teachers were killed. On Monday, the man accused of killing 10 black people in a New York City grocery store pleaded not guilty to 27 hate crime and gun charges stemming from the shooting massacre in Buffalo, which was broadcast live on social media. In June, President Joe Biden signed the first major federal gun reform in three decades, which he celebrated as a rare bipartisan deal. But individual states are already looking at ways to deal with it.