Harrington was born in Savannah, Georgia and raised in The Bronx, New York. His first role was Aulon in Luc Besson’s The Messenger: The Story of Joan of Arc (1999). He soon afterward nabbed prominent roles in films such as The Hole (2001), Ghost Ship (2002), and Wrong Turn (2003). Harrington also appeared in the Steven Spielberg sci-fi drama Taken, in which he played Jesse Keys, an abductee of aliens.
In September 2008, he joined the cast of the Showtime TV show Dexter as Detective Joseph “Joey” Quinn.
In December 2008, he played a guest role on Gossip Girl playing Jack Bass. He reprised his role through guest appearances in season three of the show.
In January 2012, it was reported that Harrington would return to Gossip Girl in the “last third of the season”. In the same month, he made a guest appearance in the season three premiere of Justified, playing Fletcher “The Ice Pick” Nix. He also played a small role in The Dark Knight Rises (2012) as a police officer and had a role in the Nicolas Winding Refn 2016 thriller film The Neon Demon.
In 2018, he joined the cast of Elementary as Michael, a serial killer and fellow member of Narcotics Anonymous with Sherlock Holmes.
Monsters don’t get to live happily ever after.
It’s a hard acomplishment to get someone to actually love a serial killer. But Dexter is one of those few attempts that works. It’s not forced upon you – the show doesn’t shove the whole “well this serial killer had a terrible childhood…” in your face. And it doesn’t need to in order to get you to love its main character. You just do.