Minor Character: Las Vegas
Name Jeffrey Forsythe
Gender Male
Family Marcia Forsythe (sister)
City Las Vegas
Pathology Mass Murderer
Serial killer
No. of Victims 5-7
Status Incarcerated
Portrayed By Mark Moses
First Appearance Risky Business Class

Jeffrey Forsythe is a mass murderer responsible for a plane crash that killed five people in Season Thirteen of CSI:Crime Scene Investigation.


Forsythe worked as a lawyer for the Lowell family, a rich family with a successful entrepreneur for a patriarch. Forsythe was secretly embezzling from the family while managing their estates and assets. To keep the con solidified, he likely caused the car crash that killed Helen Lowell, one of the family's daughters. In that same crash, his sister Marcia was left paralyzed and catatonic, left on life support to pose as Helen. She was transferred to Tranquil Hours, a care facility, and bribed Dr. Paula O'Keefe to manage the care or Marcia as part of the ruse. Donations would be sent to the facility from Helen's trust fund to disguise the daylight robbery so Forsythe would take the money for himself. However, an estranged daughter, Jordan, was gathering DNA samples to confirm her family links for child support. Knowing his con and embezzlement would stop if unraveled, Forsythe arranged for the plane she'd fly in to be sabotaged, stealing tools from mechanic Hal to get the door loosened enough that it wouldn't be detected until it dislodged in the air. Forsythe then got Jordan a ticket on the flight to set up her death.

Season Thirteen[]

Risky Business Class[]

When the plane pressurizes, the door can't keep secure and eventually swings open. The pilot, Keith Mannheim, is thrown out of the cockpit and lands in a house pool in Henderson. The plane crashes while narrowly missing the Vegas Strip and the Mediterranean casino. Terrorism gets ruled out eventually when the door's tampering is found in the wreckage. When Jordan is revealed to be the intended targeted, her DNA kit is investigated. To cover his tracks, after the police see Marcia and Dr. O'Keefe in the home, Forsythe has Marcia and O'Keefe transferred out, and the room utterly sterilized and cleared of evidence, biological, documented, and otherwise. But Marcia's DNA and prints are still on her pulse oximeter, which ties to the disguise Forsythe wore during the tampering through a sibling match and identifies Marcia, revealing Forsythe's murders and motive. He's arrested at his private plane, with Dr. O'Keefe having been tracked and fully confessing, presumably resulting in Forsythe's incarceration shortly after.

Known Victims[]

  • Unknown date:
    • Helen Lowell (killed in a car crash)
    • Marcia Forsythe (severely injured in a car crash; left with permanent paralysis and catatonia)
  • December 12, 2012
    • Tresser Park plane crash
      • Keith Mannheim (pilot, sucked out of the plane when the door blew)
      • Charles Harrigan
      • Grant Abbott
      • Jordan Lowell (intended target)
      • Thurston Mayfield

Known Accomplice[]

  • Dr. Paula O'Keefe (incarcerated)


CSI:Crime Scene Investigation
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Season 13 - - - - - - - - - X - - - - - - - - - - - - N/A 1
Total 1