Criminal Minds: It's a boy for Criminal Minds star A.J. Cook! The 30-year-old actress and her husband Nathan Anderson welcomed son Mekhai Allan Andersen on Saturday, September 13th. Weighing in at 7 lbs, 10 oz and 20 inches long, Mekhai was born at 8:50 p.m. Congrats again to A.J. and Nathan!