Nathan Fillion Richard Castle Actor Stana Katic NYPD Captain Kate Beckett Actor Susan Sullivan Martha Rodgers Actor Molly C. Quinn Alexis Castle Actor Ruben Santiago-Hudson Captain Roy Montgomery Actor Tamala Jones Lanie Parish Actor Jon Huertas NYPD Detective Javier Esposito Actor Seamus Dever NYPD Detective Kevin Ryan Actor Sonya Leslie Valerie Thompson Guest Star Arye Gross M.E. Sidney Perlmutter Guest Star Ron Melendez Jeff Dilahunt Guest Star Josh Daugherty Trent Wellesley Guest Star Jill Andre Lenanne Wellesley Guest Star Hattie Winston Sally Niedermeyer Guest Star Gregg Henry Winston Wellesley Guest Star Andrew W. Marlowe Executive Producer Armyan Bernstein Executive Producer Barry Schindel Executive Producer Rob Bowman Executive Producer Laurie Zaks Executive Producer Terence Paul Winter Writer Jonathan Frakes Director