BOSTON — James “Whitey” Bul­ger is an old man now.

He wears reading glasses. His hair is pure white, but not much remains. And when he stood up in a federal courtroom Wednesday morning to finally face the music, to stand trial for a lifetime of gangster crimes, he rose slowly, no longer the menacing Irish mob boss who allegedly scratched out 19 lives while the FBI looked the other way.

Wearing a long-sleeved green shirt, jeans and sneakers, Bulger sat passively as a prosecutor described his younger, more sinister years as leader of the Winter Hill Gang, including the time he allegedly marched a safecracker named Arthur “Bucky” Barrett to a set of cellar stairs after torturing him in a chair in pursuit of $40,000 from a bank robbery....