The Trinity Killer
Character Profile
Portrayed By
John Lithgow
First Appearance
Living the Dream
Last Appearance
The Getaway
Full Name
Arthur Mitchell
The Trinity Killer
Alan (to Tarla Grant)
Manner of Death
Killed by Dexter Morgan
60 (at death)
Personal Status
Marital Status
Sally Mitchell (deceased)
Immediate Relatives
Henry Mitchell (father; deceased)
Marsha Mitchell (mother; deceased)
Vera Mitchell (sister; deceased)
Christine Hill (daughter; deceased)
Jonah Mitchell (son)
Becca Mitchell (daughter; deceased)
Professional Status
College Tutor
Volunteer for Four Walls One Heart

Church deacon
Serial Killer

Killer Profile
"The Trinity Killer"
Number of Victims
At least 267
Modus Operandi
Straight razor, hammer (or another weapon capable of bludgeoning).
Killing Method
Child Murders: Each boy is subdued, held captive for several days before being sedated and buried alive in concrete.

Bathtub Murders: Mitchell subdues the woman, removes her clothes, takes her into a bath with her before incising her femoral artery with straight razor. Death by exsanguination.

Jumper Murders: Mitchell verbally forces a woman to jump from a ledge.

Bludgeoning Murders: Using any one of a number of blunt instruments, Mitchell repeatedly bludgeons a man's head.

Method of Disposal
Mitchell does not dispose of the bodies for the bathtub, 'suicide' or bludgeoning murders. He does, however, bury alive the ten-year-old boy.
At a young age, Mitchell witnessed his sister die in the shower (implied to be his fault, albeit indirectly). His mother then committed suicide and his father was bludgeoned outside a bar.

For info regarding the character behind the serial killer, visit here.

The Trinity Killer is a character in Season 4 of DEXTER.

He is a Serial Killer that kills in cycles of three victims: a young woman in a bathtub, a middle-aged mother whom he coerces into suicide, and a middle-aged father whom he bludgeons to death. Later, it is shown that he actually kills in cycles of four, the first victim being a ten-year old boy who is buried alive in cement whilst unconscious, five days before a woman is killed in a bathtub. He has been killing for about 30 years all over America and probably has the highest kill-count of any character in the series.

Trinity is thought to be a lone-wolf by Special Agent Frank Lundy, however as Dexter Morgan stalks him, he comes to realize that he is a family man. Trying to overcome marital problems with his wife Rita Morgan, Dexter desires to learn how Trinity's able to balance his family life with his secret life as a heinous killer. He soon comes to know that Trinity is abusive and controlling, as both a father and a husband, and is thus easily able to pursue his extra-caricular activities at will (since his family does not have to deal with his abuse during his frequent absences). Dexter knows that he could never be a monster to his family, like Trinity and therefore, comes to despise him, rather than look up to him. He eventually kills Trinity, but his recurrent failures in dealing with him lead to his wife's death by Trinity's hands (which he realizes after killing him).

Named Victims



  • Vicky Noonan
  • J. Lewitt - 3/12/1993
  • I. Rosengard - 9/5/1994
  • A. Darakjan - 2/26/1995
  • Loretta Kellerman
  • M. Bogert - 9/16/1997
  • L. Candace - 8/23/1998
  • J. Spaan - 3/9/1999
  • H. Grodman - 10/7/1999
  • Anita Soloman
  • L. Fisher - 5/11/2001
  • R. Goldman - 10/24/2002
  • K. Watkins - 4/15/2003
  • A. Goff - 5/11/2005
  • J. Meltzer - 9/18/2006
  • R. Cornelius - 7/20/2007
  • Tamera Klaman
  • L. Spheeris - 7/20/2008
  • Julie Hillard - 9/20/2008
  • Lisa Bell - 9/21/2009


  • D. Webster - 3/17/1993
  • E. Hemming - 9/10/1994
  • N. Reiss - 3/3/1995
  • J. Snisse - 9/21/1997
  • R. Elliot - 8/28/1998
  • R. Golden - 3/14/1999
  • C. Endless - 10/14/1999
  • P. Ford - 5/16/2001
  • J. Lewis - 10/29/2002
  • A. Asarcca - 4/20/2003
  • L. Pickford - 5/16/2005
  • J. Antonoff - 9/23/2006
  • R. Hermosillo - 7/25/2007
  • J. Leiberman - 7/25/2008
  • Tarla Grant - 9/26/2009


  • S. Hunter - 3/22/1993
  • J. Roberson - 9/15/1994
  • D. Freiburn - 3/8/1995
  • E. Newman - 9/26/1997
  • R. Dermott - 9/2/1998
  • B. Ball - 3/19/1999
  • F. Calvert - 10/19/1999
  • A. Severse - 5/21/2001
  • C. Moreno - 11/3/2002
  • J. Jones - 4/25/2003
  • A. Roman - 5/21/2005
  • J. Ellis - 9/28/2006
  • B. Polaski - 7/30/2007
  • R. Bear - 7/30/2008
  • Earl Doorman - 10/1/2009

Other Victims

The following victims are the few kills that Arthur has made outside of his kill cycle.

  • Henry Mitchell - Arthur's father. Though it is never confirmed, it is possible, due to the things he shouts at his later bludgeon victims. It is possible that Henry was Arthur's first kill, prior to the cycle.
  • Kyle Butler - Another bludgeon victim that he killed while he was trying to find Dexter. This one was done after he had failed at starting a new cycle. This man doesn't fit into Trinity's cycle because Arthur just wanted to kill him to silence him.
  • Rita Morgan - A bathtub victim. She is considered outside of his cycle for two reasons: He had yet to succeed in burying a young boy in cement, and she didn't fit the normal characteristics of his bathtub victims.

Attempted Victims

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