Greevey is happily married to his wife Marie, with whom he has three children. A conservative Irish Catholic, he sometimes looks down upon people, even murder victims, whose lifestyles conflict with his beliefs. For example, his opposition to abortion makes him uncomfortable investigating the bombing of a family planning clinic, which causes some friction with Logan, who is pro-choice. However, he seems at least tolerant of adultery, noting that while he himself has never cheated on his wife, "I don't judge. You can never know someone else's story".