The best tactic I found to accomplish this is to tip off the reader to things the character is unwilling to admit. One way is revealing the character as an unreliable narrator, one willing to lie to himself and to others - even if he doesn’t know he’s doing it. For example, Junior’s assessment of his relationship with Molly, his lover, especially in conversation with her, is cold and deliberately hurtful. But his actions toward her, his admiration for her beauty, his wanting her with him, his resentment of her boyfriend, and his immediate desire to keep her out of the trouble he’s about to get into tell a different story. The real story.

It’s a similar case with his sister, Julia. Junior is flip and callous about his father’s murder, and although in the excerpt he uses Julia to taunt and annoy the police, his fierce protectiveness of his younger sister also comes through. So while Junior’s outward focus in the excerpt is on his own tough-guy-ness, his deep affection for and loyalty to others (a truer, more mature breed of toughness) also peeks through.

Another tactic is using the other characters to show sides of Junior that he won’t show. Molly’s known Junior since they were teen-agers and blows off most of his bluster as exactly that. She’s suffered her own tragic loss in adulthood. Molly knows anger and pain, too, and she knows that there is legitimate damage and that there are real scars under Junior’s thick skin. How she handles him tips off the reader to these truths. She’s the reader’s eye into Junior’s heart, a part of him that Junior fiercely protects but that the reader needs to see.

Nat Waters, the lead detective in the murder, performs a similar function. He has no reason to like Junior, and he doesn’t. But he knows from experience as a cop that big pain always comes with losing a parent and that it’s about to hit Junior. Like Molly, Waters knows things about Junior’s past with his father that lend him more empathy toward the young man and the ability to see through Junior’s attitude. Again, the reader is reminded that there’s a damaged heart and soul under all that bravado.

Through the other characters, Junior is rounded-out and humanized, despite how hard he works to dehumanize himself. By the end of the excerpt, Junior is no longer just a foul-mouthed jerk but also broken-hearted boy whose days of refusing to see the truth about himself and his life are quickly coming to a shattering end.