"Are you being disrespectful?" I said.
"I would say so, yes."

Paul Giacomin is Spenser's adoptive son. Spenser is hired by Paul's mother in Early Autumn to retrieve Paul from his father during a custody dispute. Over the course of the book, although Paul is withdrawn and sullen (Spenser calls him an "unlovely bastard") Spenser realizes that neither of Paul's parents care for him as a person, and Spenser takes Paul under his wing, bringing him up to build a cabin in Maine and teaching him how to weightlift and box. In doing so he learns that Paul's true interest is dance, and by the end of the book blackmails Paul's parents into sending him away to dance academy. Paul later becomes a successful dancer, writing and directing his own show (Back Story) and, later, teaching dance in New York.

Paul is tall (6'2 or 6'3) and slender, in excellent physical shape. He's one of the few people Spenser trusts and loves.

Interestingly, Spenser's experience with Paul in Early Autumn  - interspersing visits to the ballet with baseball games - is similar to that reported by Robert Parker's son David in a eulogy.