Ryan O'Halloran
Ryan O'Halloran Cold
Name Ryan O'Halloran
Title Detective
Affiliation NYPD
Division Crime Scene Unit
Precinct One Police Plaza
Occupation Police officer
Family Unnamed sibling
Unnamed nephew
Status Deceased
Actor Mike Doyle
First Appearance "Choice"
Last Appearance "Zebras"

Ryan O'Halloran was a Forensics Technician who worked for the NYPD's Crime Scene Unit.

O'Halloran is first confirmed as a detective when Oliver Gates cross-examines Detective Stabler. (SVU: "Gone")

O'Halloran was dedicated and thorough with his work. He despised it when detectives rushed to judgment without weighing the forensic evidence before them. (SVU: "Fat")

In June 2009, when a gas trap nearly killed Detectives Odafin Tutuola and Elliot Stabler, O'Halloran told them they are lucky to be alive. O'Halloran was tragically killed by his assistant, Dale Stuckey, after he discovered evidence that Stuckey had murdered attorney Julia Zimmer. (SVU: "Zebras")


  • Managed to retrieve a fingerprint belonging to Deacon Brinn from a wad of gum stuck to Ronsen's shirt.
  • O'Halloran investigated the crime scene of Vicky Riggs. He didn't find any fingerprints on the victim's phone.
  • O'Halloran also investigated the footprint found outside of Josie Post's apartment. He determined that her intruder lowered himself from the apartment complex and entered her apartment through the window.
  • Found traces of gasoline on the shovel used to bury Sierra Walker, indicating that she was buried near a gas station.
  • Managed to retrieve a blood sample from a mosquito found in the car of Julia Zimmer, which connected Stuckey to her murder.
  • Case transferred to another technician due to O'Halloran's murder.


  • O'Halloran is survived by at least one sibling and at least one nephew. ("Quarry")
  • He was a vegetarian. ("Lead")
  • He didn't like his assistant Dale Stuckey and was eventually murdered by him. Before this, when he found out just how incompetent Stuckey was and Stabler threatened to kill him, O'Halloran offered his assistance, saying he'd dump the body.
  • O'Halloran has the highest episode count of any recurring character in Law & Order: Special Victims Unit.


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