A monthslong investigation by CBS News punctures Thomas Crooks’ secrecy to reveal the broadest portrait yet of the lonesome ...

His would-be assassin, 20-year-old Thomas Matthew Crooks, had first caught the attention of law enforcement that day when spectators noticed him acting strangely outside the event.

The shooter was later identified as Thomas Matthew Crooks, 20, and he was killed by law enforcement. Crooks appeared to have acted alone and did not belong to any particular political leanings.