Aidan Quinn stars as Homicide Lieutenant Kevin Sweeney in NBC's gritty crime drama "Prime Suspect."

A native of Chicago, Quinn got his start in the theater at age 19. One of his most notable stage credits is "Hamlet," in which he acted in the title role. On Broadway he starred in "A Streetcar Named Desire" for which he won the Theatre World Award. His Off-Broadway credits include Sam Shepherd's "Fool for Love," "Lie of the Mind," "The Exonerated," "Salome" and, most recently, "Conversations in Tusculum."

His numerous television credits include "An Early Frost" and "Bury My Heart at Wounded Knee," both of which garnered him an Emmy nomination. 

Quinn has starred in more than 50 feature films, among them "Desperately Seeking Susan," "Avalon," "At Play in the Fields of the Lord," "Benny and Joon," "Legends of the Fall," "The Assignment," "Songcatcher" and "Unknown." His upcoming film projects include "If I Were You" opposite Marcia Gay Harden and "Sarah's Key" with Kristin Scott Thomas.

In Ireland, Quinn has appeared in many films, including "Michael Collins" and "This Is My Father," written and directed by his brother Paul and filmed by his brother Declan. Other credits include "Song for a Raggy Boy," "The Eclipse" and "32A," which was directed by his sister Marian.