An Acquaintance of the Legendary Howard Brodie, Now a Security Guard

or was, five years ago.

He worked with the actual guy who did stuff like this :

What I want to know : what tools did Brodie carry with him and how long did this one take to do, and did he work off a photograph. Stunning

As for Gary, NYT says how he went from being at happening events to working the shift.

His tips for aspiring courtroom artists : 

1. Capture likeness - audience should never have to guess
2. Portrait is not enough. The context has to be captured.
3. News judgement.
4. Fairness and objectivity.
5. Responsibility - you are capturing history.
6. Work quickly - capture something that is transient.
7. Conduct yourself with decorum. You are representing the press.
8. Work should speak for itself with functionality and credibility.