Dexter: Season 4 (2009)

Season 4

Critics Consensus

The inherent comedy of Miami's favorite psychopath contending with domestic bliss and the unspeakable horror of John Lithgow's Trinity killer coalesce into one of Dexter's most sensational seasons.



Critic Ratings: 33


Audience Score

User Ratings: 864

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Air date: Sep 27, 2009

Dexter preps for his wedding day but must first divorce himself from Miguel, which proves most difficult as Miguel is a prominent D.A. and Dexter's best man. Sylvia confides in Rita that Miguel has been seeing an ex-lover Debra digs up new clues in the Skinner case.

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Air date: Oct 4, 2009

Dexter mishandles crucial evidence in a case. His carelessness could come back to haunt him and impact Agent Lundy's investigation into the latest Trinity Killer slayings.

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Air date: Oct 11, 2009

When a rash of vandalism strikes Dexter's new neighborhood, the increased vigilance of his neighbors impacts his ability to take care of his side business, and it doesn't help matters that he is temporarily unable to drive. As for the Trinity Killer, Dexter is developing an appreciation and admiration for his incredibly impressive technique.

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Air date: Oct 18, 2009

Rita and the children take an out-of-town trip, leaving Dexter behind for some long-overdue rest and relaxation, which he instead channels into chasing down a new victim. But his investigation turns up some surprising results and he begins to empathize with the killer, a policewoman who murdered her entire family.

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Air date: Oct 25, 2009

Dexter decides to take on the Trinity Killer case on his own; Debra takes the blame for an unforeseen event that she had no control over; and Rita discovers one of Dexter's secrets and begins to question just how much she really knows about her mysterious mate.

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Air date: Nov 1, 2009

Dexter steps up his own investigation into the Trinity Killer case when he realizes the police department is making major headway; Debra's frustration over getting shut out of her own case leads her to make compromising decisions that could impact her job. Elsewhere, Batista and LaGuerta have second thoughts about personal and professional decisions that may affect their jobs and relationship; and Dexter gets romantic advice from an unlikely adviser.

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Air date: Nov 8, 2009

When Miami Metro uncovers a string of homicides and connects them to a well-known photographer, Dexter turns his focus on this new perpetrator in hopes of taking a shot at bringing him down. But Quinn's interest in Dexter's nocturnal pursuits puts a crimp in his plan. Meanwhile, the Trinity Killer is still at large and Harry urges Dexter to stay with the case; Debra returns to work and is frustrated by all the undue attention and kid-glove treatment.

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Air date: Nov 15, 2009

Dexter learns the Trinity Killer may be taking his act on the road when the homicidal maniac plans an out-of-town trip. To gather more insight into the mind of the murderer, Dexter decides to accompany him, but isn't really ready for some of the shocking revelations of which he becomes privy. Back in Miami, a technicality is keeping Debra off the Trinity case, but she utilizes others in the department to get her opinions registered.

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Air date: Nov 22, 2009

Dexter studies those closest to Arthur in an attempt to understand the psychology behind the Trinity Killer's actions; Rita's Thanksgiving-dinner plans are complicated when her full house gets even fuller with the addition of some unexpected guests; Batista sees some closure on a troubling old case; and Debra's continued pursuit of the Trinity Killer may prove a threat to Dexter.

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Air date: Nov 29, 2009

Just when Dexter figures he has a full understanding of the heinous Trinity Killer, a 10-year-old boy goes missing and Dexter must rethink his strategy in a race to find the youngster. Elsewhere, Cody feels the need to defend one of his stepfather's lies; Masuka is conflicted about revealing what he witnessed at Thanksgiving dinner; and Debra's recently unearthed secret about one of Miami's finest puts her in a touchy situation.

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Dexter: Season 4 Photos

Tv Season Info

John Lithgow joins the cast as Arthur Mitchell in series 4, which centers around the search for the Trinity Killer. Along the way, Dexter (Michael C. Hall) mishandles crucial evidence in a case, Deb (Jennifer Carpenter) takes the blame for an unforeseen event, and Rita (Julie Benz) discovers one of Dexter's secrets. Other familiar faces in the fourth season include Keith Carradine, Desmond Harrington, Lauren Velez and David Zayas.

Cast & Crew

Michael C. Hall
Dexter Morgan
Jennifer Carpenter
Debra Morgan
Julie Benz
Rita Bennett
David Zayas
Angel Batista
James Remar
Harry Morgan
C.S. Lee
Vince Masuka
Lauren Vélez
Maria LaGuerta
John Lithgow
Arthur Mitchell
David Ramsey
Anton Briggs
Courtney Ford
Christine Hill
Preston Bailey
Cody Bennett
Mary Mara
Valerie Hodges
Geoff Pierson
Captain Tom Matthews
Julia Campbell
Sally Mitchell
Jake Short
Scott Smith
Brando Eaton
Jonah Mitchell
Vanessa Marano
Rebecca Mitchell
John Goldwyn
Executive Producer
Sara Colleton
Executive Producer
Clyde Phillips
Executive Producer
John Dahl
Scott Reynolds
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Critic Reviews for Dexter Season 4

Audience Reviews for Dexter: Season 4

  • Aug 15, 2020
    In Season 4 Dexter faces new challenges as he balances married life with his Dark Passenger. Retired FBI agent Frank Lundy returns to Miami to seek Dexter's help in looking for a mysterious serial killer he calls the Trinity Killer, who commits three seemly unconnected murders in a cycle repeatedly throughout various cities; meanwhile Angel and LaGuerta begin a secret relationship and Quinn gets close to a reporter who has questionable intentions. John Lithgow joins the cast as Trinity and gives quite a performance. Equally as good is Courtney Ford as the mysterious reporter Christina Hill, who proves pivotal to the story arc. But as good as the whole Trinity plot is (and it is), it's kind of undercut by the WTF Angel/LaGuerta romance. Still, the heart of the show is Dexter, and his struggle to conform to a family life with a wife and kids proves to be a compelling theme. While it doesn't quite reach the highs of previous seasons, Season 4 of Dexter is remarkable strong and takes the series in some interesting new directors (particularly given the shocking season finale).
    Dann M Super Reviewer
  • Mar 14, 2021
    John Lithgow is a great actor who plays an amazing villain. Season 4 might be the best season yet, with a lot of twists.
  • Feb 01, 2021
    Jaw-dropping, ridiculously intense and, above all else, brilliant.
  • Jan 20, 2021
    Daddy Dexter, Lecherous Lithgow, what's not to love?
  • Jan 19, 2021
    This is my favorite season of Dexter! John Lithgows Character, The Trinity Killer is the perfect role for him! He makes it as the darkest foe Dexter has faced yet. I feel like this is the darkest season of all and thats one of the many things that make it the best! A must watch of all seasons! Just wait until the ending. You'll see.
  • Oct 29, 2020
    The best season of Dexter. If you can't watch it all (and you don't really have to), make sure that you don't stop before the end of season 4. The highlight of the season (and almost the show) is the Trinity Killer - the perfect enemy, friend and mentor for Dexter.
  • Sep 29, 2020
    This was a much better season than the third season. This season had easily the best villain of the past four seasons: Arthur Mitchell, played phenomenally by John Lithgow. And, it was great watching Dexter juggle his family life and secret life of killing, especially since he has a baby. And, the last moment of this season (no spoilers in case anyone reading this hasn't seen it) left my mouth hanging to the floor. Fantastic season overall.
  • Sep 06, 2020
    The best season of the lot! Absolutely brilliant!! I feel like this is the season where Deb finally stop being annoying and starts to become a character you actually like!
  • Jun 01, 2020
    A new classic on the TV series scene
  • May 17, 2020
    The one villain-hero we love to root for

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