The FBI concluded in 2025 that Crooks acted alone. Investigators said they found no accomplice, no foreign connection and no manifesto, and could not establish a motive. His online searches had included both Trump and Biden. [1][2]

The failures were on the Secret Service’s side. The roof Crooks fired from was outside the security perimeter and nobody was posted on it, local police had spotted him acting suspiciously, and radio communication between agencies broke down. The agency said it suspended six employees in 2025; the DHS inspector general documented planning and communication failures. [3][4][5]

The FBI said in July 2024 that what hit Trump’s ear was a bullet, “whether whole or fragmented into smaller pieces.” That settled an early argument about glass or shrapnel. [6][7]