The gunman who attempted to shoot Donald Trump at a rally in Pennsylvania on Saturday carried out internet searches before the attack for images of both Trump and Joe Biden, as well as the dates of both the current Republican National Convention and next month’s Democratic National Convention.Top FBI and secret service officials told members of Congress on Wednesday that the initial investigation into the shooting had thrown up new information about the would-be assassin’s interests, but had brought agents no closer to finding a motive.The suspect, named as Thomas Crooks, 20, was a registered Republican but had no known political ideology and had searched digitally for details of many public figures.Those included a member of the British royal family, the New York Times reported. Other high-profile figures that were on the gunman’s radar included Christopher Wray, the FBI director, Merrick Garland, the US attorney general, and top congressional party leaders such as Mike Johnson, the Republican leader of the House, and Hakeem Jeffries, the Democratic minority leader.Officials stressed to lawmakers that the significance of the searches found on the shooter’s phones and other digital devices was not clear.The secret service is coming under mounting pressure over security arrangements at the rally site in Butler, Pennsylvania. In the course of the briefings with Congress, law enforcement officers disclosed that the gunman had been sighted and noted as suspicious about an hour before the shooting, but he had then disappeared.Some nineteen minutes before shots rang out, the man was spotted again, according to the Republican senator from Utah, Mike Lee. According to the local police chief, Tom Knights, an officer from Butler Township had climbed up the side of the building from which the shooter struck, located about 150 metres from the stage where Trump was speaking.A CNN report said that in a statement Knight disclosed that the officer had seen the shooter, who pointed his rifle at him.“The officer was in a defenseless position and there was no way he could engage the actor while holding onto the roof edge. The officer let go and fell to the ground,” Knights said.The new details have left some lawmakers angered, both at the apparent lack of police intervention despite sightings of the gunman, and at why Trump was allowed to take to the stage and address the crowd for several minutes before he was shot at. Kimberly Cheatle, the director of the embattled secret service, is likely to have to face such questions on Monday when she comes before the House Oversight Committee.Two phones belonging to the gunman were found at the rally site, one on the roof of the warehouse beside his body after he was killed by secret service snipers, and the other during a search of his house in Bethel Park, Pennsylvania. Lawmakers were told that among his online searches the shooter had been looking for information on major depression disorder, prompting a new line of inquiry that he might have been struggling with mental health issues.