He is mainly known for his role on Law & Order: Special Victims Unit as Ryan O'Halloran, Adam Guenzel in Oz,[1] and from 2018 to 2023 on New Amsterdam as Martin McIntyre.
Doyle also appeared as Jamie Perse, a small-time crook, in the 1996 television miniseries Titanic (also starring Peter Gallagher and Catherine Zeta-Jones).
His death in the season 10 finale of Law & Order: Special Victims Unit ended a successful six-year run as forensic tech Ryan O'Halloran on the show.
[6] In 2014, he portrayed songwriter and record producer Bob Crewe in the film of the hit musical Jersey Boys, based on the story of Frankie Valli & the Four Seasons.
[7] He also appeared in the music video "I Wanna Get Better" by Jack Antonoff's band Bleachers, alongside Retta.