While Mac typically displays a somber and serious demeanor, he does have a lighter side; he teases Sheldon Hawkes in episode 2.02 "Grand Murder at Central Station", by telling the young CSI, who is taking a quick lunch break, that "eating is frowned upon", and when Hawkes asks to borrow a little girl's teddy bear(Franklin) because he may have evidence on him, Mac jokes "So did Franklin tell you anything, or did he lawyer up?". Later in Season 2, Lindsay Monroe discovers that he plays bass guitar in a jazz club when he is off-duty. Mac also is shown playing bass in the episode 4.04 "Time's Up", after receiving a goodbye letter from Peyton.