Tony Shalhoub Adrian Monk Actor Ted Levine Capt. Leland Stottlemeyer Actor Traylor Howard Natalie Teeger Actor Jason Gray-Stanford Lt. Randall Disher Actor Howie Mandel Ralph Roberts Guest Star Adam Kaufman Brother Ted Guest Star Sunny Mabrey Sister Sally Guest Star John Ross Bowie Tom Donovan Guest Star Kerry O'Malley Susan Donovan Guest Star Stanley Kamel Dr. Charles Kroger Guest Star John Bobek Brother Zack Guest Star Christina Knizner Sibling Girl Guest Star Kimberly Douglas Cult Sibling Guest Star Anton Cropper Director Josh Siegal Writer Dylan Morgan Writer