Donald Trump has agreed to participate in a victim interview with the FBI regarding his attempted assassination earlier this month, the bureau told reporters on Monday. This comes as authorities continue their investigations into the 13 July shooting in Butler, Pennsylvania, where 20-year-old Thomas Matthews Crooks fired eight shots from an assault rifle which hit and injured the former president, killed a rally attendee and injured several others. Crooks was killed by government snipers moments after the shooting began. On Sunday, new details around the shooting emerged from text messages between local security units, obtained by the Republican senator Chuck Grassley and published and verified by the New York Times, including that local law enforcement had spotted the shooter 30 minutes earlier than what officials had previously said. The published text messages show that a local countersniper first noticed a man, who was later identified as Crooks, loitering in the area where the countersnipers were set up more than 90 minutes before the shooting occurred. The Times reported that at 4.26pm, the countersniper alerted his colleagues of Crooks, and that he had parked near their vehicles and was sitting on a picnic table near the warehouse, where several countersnipers were, outside the fenced area of the grounds where Trump would be appearing later. The countersniper told his colleagues that Crooks knew they were there and saw him leaving with his rifle. One of the countersnipers took pictures of Crooks and the photos were shared in a group chat and another text went out among the local officers at 5.38pm, saying they should inform the Secret Service, per the New York Times. “Kid learning around building we are in. AGR I believe it is. I did see him with a range finder looking towards stage. FYI. If you wanna notify SS snipers to look out. I lost sight of him,” read one of the texts, accompanied by photos of Crooks. One of the two remaining countersnipers reportedly ran out of the building attempting to keep eyes on Crooks until other law enforcement arrived, per Butler County officials, but Crooks ran off, taking a backpack with him. At 6pm, one officer in the group texts guessed that Crooks was moving toward the back of the warehouse complex and away from the event, the Times reported. But instead, Crooks climbed on to a building in the complex closest to the stage. At 6.11pm, Crooks began firing, grazing Trump’s ear, killing a rally-goer and injuring several others. Moments later, Crooks was shot and killed on the roof of a warehouse that was connected to the one the countersnipers were stationed in. The newly released messages also suggest that the shooter was often one step ahead of security forces and law enforcement. The New York Times reported Crooks had scoped out the rally site a day before the Secret Service did on 8 July. The report also states the Secret Service excluded the entire warehouse complex from its inner security perimeter. This meant that on the day of the rally, Crooks was able to get to the building without passing through a security screening. After the Secret Service walk through on 8 July, the Times reported that the agency had asked local agencies to provide more help, and that text messages showed that Beaver county struggled to find enough volunteers to cover the 12-hour shift. Questions continue to be asked about the apparent failures in communication between different law enforcement agencies and how someone was able to get to close to assassinating Trump. Local police officers on a special tactical team, who were assigned to help protect Trump on 13 July, have also said they had no contact with Secret Service agents before the gunman opened fire. “We were supposed to get a face-to-face briefing with the Secret Service members whenever they arrived and that never happened,” Jason Woods, lead sharpshooter on the Swat team in Beaver county, Pennsylvania, told ABC News over the weekend. The Secret Service has not commented directly on the remarks by Woods. But an agency spokesperson, Anthony Guglielmi, has said the Secret Service “is committed to better understanding what happened before, during and after the assassination attempt of former president Trump to ensure that never happens again”. Separately, members of Trump’s Secret Service detail and his top advisers have questioned why they were not told that local police assigned to guard the outer perimeter of the fairgrounds had spotted a suspicious person who turned out to be the would-be assassin. Last week, the FBI director, Christopher Wray, testified to the House judiciary committee that the shooter appeared to have used a drone at the rally location about two hours before the attack, to scope out an area about 200 yards (182m) from the stage where Trump was scheduled to speak. The drone was found in the gunman’s car, along with two explosive devices. According to the New York Times report, the Secret Service did not seek permission to use a drone for the rally. Wray also testified that the AR-style rifle used in the attack may have had a collapsible stock, making it easier to conceal, and that in the days leading up to the shooting, Crooks had searched online for information about the 1963 assassination of John F Kennedy. Despite the new information about the shooter’s focus on the Kennedy assassination, Wray said that the FBI had yet to find any clear indication of Crooks’ motivations or ideology. “It does appear he was interested in public figures more broadly,” he said. According to the New York Times, Crooks had started searching online for information on well-known figures, including Wray, US attorney general Merrick B Garland, Joe Biden and Trump, and he had also looked up “major depressive disorder”. In the immediate days after the shooting, Trump initially called for unity, writing on Truth Social that “in this moment, it is more important than ever that we stand United, and show our True Character as Americans, remaining Strong and Determined, and not allowing Evil to Win.” Delegates at the Republican National Convention also made much of how Trump’s campaign would pivot to a more message less divisiveness. But although Trump’s keynote speech at the convention began with him saying all Americans are ‘bound together by a single fate’, he soon reverted to attacking Democrats over the numerous criminal convictions he is facing and falsely accused the party of cheating in the 2020 election. More recently, on Saturday, Trump told supporters in a speech in Minnesota that the shooting may have made him “worse”. “I want to be nice,” Trump said. “They all say, ‘I think he’s changed. I think he’s changed since two weeks ago. Something affected him.’” “No, I haven’t changed”, he continued. “Maybe I’ve gotten worse, actually. Because I get angry at the incompetence that I witness every single day”.