Like many of the characters in Jellicoe Road, we get to see two versions of Santangelo's dad—the young cop who visits the scene of the Markham/Schroeder accident and investigates Webb's disappearance, and the hardened older officer who sees the past come back to haunt him as Taylor grows curious about her origins. Even though he's complicit in Hannah's desire to keep the truth about Taylor's family under wraps, he doesn't expect his son's competition with her in the territory wars to force him to bring out the truth.
Santangelo's history with the five is deeply rooted, going back to literally the very beginning of his job on the force. Hannah's manuscript recounts:
During his first week on the job five years ago, he had been called out to an accident on the Jellicoe Road. It had been the first time he had ever seen dead bodies, and he remembered how he had throw up on the side of the road while his sergeant told him to pull himself together. (14.11)
Whoa—talk about getting shoved into the deep end. No wonder it's hard to deal when Taylor comes to him asking for the truth about her past.
At first, Santangelo's dad is reluctant to give Taylor any information. When she comes to his office and demands that he tell her who she reminds him of, he at first backs away, revealing only that she reminds him of Hannah and that she "will always come back for you" (19.24). He balks at the idea of revealing the truth about how the Hermit died, though we can't really blame him. After all, Taylor kind of played a crucial role in that incident and he probably wants to spare her the anguish of learning too much at once.
But later, after the heart stopping action of the Lachlan House fire, Santangelo's dad seems to change his tune. As Taylor tells an unconscious Jessa the story of how the five met, she eventually becomes overwhelmed by what's happening: "When I can't tell the story anymore because it breaks my heart," she says, "Santangelo's dad takes over, because he was there that night" (25.138). Thanks, dude.
It's tough to do the ESP thing when Taylor is our point of view character, but we have this theory that Santangelo's dad's refusal to talk to Taylor about her past kind of goes along with his own trauma related to knowing the five. Could it be that the whole ordeal with his son breaking into the police station, combined with the fire and Taylor's questions, cause him to come to terms with the horror he experienced years before? In that case, Taylor and Hannah aren't the only people who experience healing from the story.