Students who knew Allen in this capacity characterized him as highly intelligent, adding complexity to his public profile after the incident.
Authorities continue to investigate Allen's background and possible motives, while the shooting has raised concerns about security at high-profile Washington events.
How does a highly-educated teacher with no criminal record become a would-be assassin?
If his family alerted police about a manifesto, why wasn't he stopped sooner?
What can be done to prevent the next attack from a seemingly 'normal' individual?
Was the security response a 'massive success' or a catastrophic failure narrowly averted?
Does creating a violent online game signal a risk for real-world violence?