Andersen is the son of actress A.J. Cook, who is currently portraying Jennifer Jareau on Criminal Minds. His father is her long-time boyfriend and later husband, Nathan Andersen. Cook announced her pregnancy in March of 2008 and her son was born on September 13, 2008, weighing 7 lbs 10 oz, with a height of 20 inches. He was christened Mekhai Allan. Cook commented: "He's such a good baby. I feel so lucky that he's mine. My husband and I feel very blessed!".
On the show, Andersen portrayed Henry LaMontagne, the son of his mother's character. He appeared in fourteen episodes in total (not fifteen, since "Hit" and "Run" are parts of a two-hour special episode).
- Criminal Minds: