Adam Lanza reportedly destroyed his computer’s hard drive before going on a rampage that left his mother, six more adults, and 20 children dead, sources said on Tuesday. “The kid knew what he was doing,” a source told The Daily Beast. “This was a planned event. There is no question about it.” The FBI is trying to retrieve the data, although some tech experts said Lanza may have overwritten the drive, wiping out the data. According to the Hartford Courant, Lanza, 20, used the computer to play violent videogames, but it’s unclear if he used it for anything else.