Kristina Maria (Ghosts of River Oaks #6)
Sue Fineman

Jack, Megan’s neighbor, understands Krissy’s grief. He lost his twin brother in a drive-by shooting. He’s attracted to the dark-haired beauty, but she’ll need time to work through her grief and guilt about not saving Megan before she’s ready for a relationship.
He does his best to protect Krissy from her sister’s killer, using humor to distract her, but he doesn’t expect Megan’s ex to target him too. He’s surprised when Megan’s ghost attaches herself to Krissy, teasing her about seeing Jack naked. He doesn’t even believe in ghosts, does he?