Season 10
Number 17
Writer Bradley Thompson,
David Weddle
Director Michael Nankin
Original Airdate April 8, 2010
Previous Episode: The Panty Sniffer
Next Episode: Field Mice

Irradiator is the seventeenth episode in Season Ten of CSI: Crime Scene Investigation.


The team discovers that a man who shot and killed a married couple is actually a victim of "Dr. Jekyll", and Langston could be the doctor's next target.


Victims: Tom and Lisa Layman, family dog (all deceased)

On the case: entire team

While her husband sits upstairs in bed, Lisa Layman leaves to bring the family's barking dog into the house. Suddenly, gunshots are heard and the barking is silent. Lisa is shown in the kitchen, having already been shot once by an intruder. As she goes to leave, she's shot again and killed. Her husband, Tom, is last seen grabbing a baseball bat.

The following morning, we see that the dog has been shot and both Tom and Lisa have been killed. In the hallway, Sara spots a bloody partial shoe impression from a construction boot. Family photos on the wall show that the couple has a young daughter, Gracie, but she has yet to be found. There are bullet holes in the door to Gracie's room, but Nick finds no blood on her bed. Using a tool from his kit, Nick fluoresces urine stains on the floor and follows them to a chest near the bedroom window. When he opens it, Gracie screams until he's able to calm her down. She begins to sob as Nick holds her.

Outside, Greg finds a tool mark under one of the windows, indicating that their killer may have jimmied it open. He's able to uncover a fingerprint when he dusts the windowsill. In the lab, Hodges tapes lift some metallic trace from Lisa's bathrobe, while Wendy finds the same trace in the bloody boot print.

The print from the windowsill comes back to the Layman's gardener. In the hospital, Nick talks to Gracie, who is able to identify the gardener from his photo. However, she's unsure as to whether he's the intruder who killed her parents. She recalls running into her bedroom after the shots were fired and hiding under her blankets. The intruder entered the room and pointed a gun at the bed, but soon became mad at himself and trashed the room, instead.

Brass interrogates the gardener, who has a rap sheet and past gang affiliations. The gardener also wears a size 11 shoe, which matches the bloody boot impression in the house. When pressed, he admits to breaking into the house the week before to steal a gaming system, but insists that he didn't kill the Laymans.

Though the gardener's boots have the same tread pattern as the bloody impression, they test negative for blood and metallic trace. Hodges informs Sara that the metallic trace is a titanium alloy, which would be more consistent with a machine shop worker rather than a gardener. Sara wonders aloud that if there was titanium dust outside the house, then there must be some outside, as well.

At night, Nick, Sara and some uniformed officers find titanium dust outside the Layman house and follow a trail of it to the house next door. There's a blood smear on a doorknob and the door is unlocked. They enter the completely dark house and find .22 caliber bullets on a desk, the same caliber that was used to kill the Laymans. In the garage, they find a workshop complete with a drill press. Water is running, causing a sink to overflow. Nick turns the water off and the CSIs hear music playing from an the basement. Down there, another drill press is still running and they discover that the music is coming from an open laptop. Sara finds the homeowner's jacket, which is covered in blood spatter.

The homeowner is identified as Jack Herson, a retired machinist. It's found that he owns a gun with the same general rifling characteristics as the murder bullets, but the gun has yet to be located. Tracking Jack by his credit card use will be impossible, as all of his cards have been maxed out for months. Langston wonders if Jack simply had enough of being behind on his bills and decided to go on a killing spree. As he tours the basement workshop, he comes across a large titanium part in the shape of an arc and stops dead in his tracks. He tells Nick and Sara that this, and several other smaller parts, are pieces of a prototype stereotactic frame used for neurosurgery. From this, Langston believes that Jack is Dr. Jekyll and hypothesizes that he killed the Laymans because they found out. They find a metal operating table nearby that, when sprayed with luminol, tests positive for a lot of blood.

Meanwhile, Jack is involved in a fender bender, which escalated into a hit-and-run after he confronted the other driver. Jack ran the driver over with his pickup truck and left the scene; the other driver survived and was taken to the hospital. The truck is later found abandoned outside of Pahrump. When Greg relays this information to Sara, she pulls up pictures she took in Jack's house. One of them is of Jack and an unknown woman standing in front of a house; a decal of the Pahrump high school's mascot can be seen in the house's window. Based on the odd five-digit house number, the police are able to narrow down where the house is.

The house belongs to Jack's aunt, Nellie Porter. A camera is slipped under a door, giving the police a clear visual of what's going on inside. They see Jack walking back and forth erratically complaining about the Layman's dog constantly barking. Outside, Brass immediately sees that something is off about Jack, who is soon seen complaining that there's something wrong with his head. As his aunt pleads for her nephew to put the gun down, he shoots and kills her. The police enter and confront Jack, who makes his way upstairs and drops his gun in the process. He begins to foam from the mouth before collapsing to the ground and dying. Meanwhile, in Jack's basement, Nick notices that the plug to the radiator is missing and that it was removed recently. Inside the pipe, he finds a note that reads "GITA 11.32." An internet search reveals that it's a passage from the Bhagavad Vita, a Hindu scripture. The passage is the same one that went through Robert Oppenheimer's mind when he witnessed the first atomic bomb blast: "Now I am become Death, the Destroyer of Worlds." Langston and Nick conclude that Jack isn't Dr. Jekyll, but, rather, one of his victims.

Catherine and Nick go over Dr. Jekyll's past "operations," noting that he has taken something personal from his victims but left something else behind inside their bodies. In autopsy, Langston and David Phillips see fresh stitches on the top of Jack's head. An x-ray of his skull shows something glowing in the middle of it. Langston remembers the radiator plug and guesses that the material they're looking at is radioactive.

Doc Robbins confirms that Dr. Jekyll planted radiation seeds into Jack's brain and tells the team that the radiation severely damaged the area of the brain that's involved with mood changes and rage. Langston believes that Jack might not have known what he was doing when he killed the Laymans and their dog. After being operated on, he would've awakened and been unable to remember what happened. Records show that Jack called his HMO and threw a tantrum when told that he couldn't get an appointment right away. Langston guesses that the dog barking was the final straw and that his not killing Gracie was the last shred of humanity he could muster. Catherine notes that three weeks ago, Jack made a cash deposit for $5,000 and, the next day, he drew up plans for the stereotactic unit and placed an order for medical-grade titanium. The team concludes that Dr. Jekyll paid Jack to build the unit then used it to operate on him. They now need to figure out where Dr. Jekyll and Jack may have crossed paths.

A test on the radiation seeds determines that they're made of iridium 192 and also contain gold. Based on their half-life, Hodges is able to figure out when they were manufactured. He also discovers that the only commercially available iridium pellets with gold substrates were manufactured and sent to St. Sebastian's Hospital in care of a Dr. William Burke 13 days ago. The hospital just happens to be in Las Vegas. Langston leaves immediately to go talk to the doctor.

At the hospital, Dr. Burke confirms to Langston and Brass that ten radiation seeds are missing, but doesn't know what happened to them. The doctor is told that the seeds were implanted into someone's brain, which led to the murders of three people. He's unable to give his exact whereabouts over the last several days, but says that his secretary can fill them in. Before departing, Dr. Burke realizes that he recognizes Langston from the book he wrote about the Angel of Death. He then starts ripping into Langston, claiming that he vilified the entire medical profession in the book. Brass tries to separate the men and starts to leave. As Dr. Burke continues to get under Langston's skin, Langston shoves him into a wall, cutting him below his eye.

In a hallway, Brass tells Langston that Dr. Burke decided not to press charges for assault after Brass brought up how losing radioactive seeds could impact the hospital. Langston listens silently as Brass gives him some advice—if he's still hung up about something that happened in the past, it would be best to let it go.

The hospital's security director tells Nick that all restricted areas in the hospital have keypad locks and that each person has to enter their personal code into them. They go through surveillance photos of the door to the nuclear medicine storage room from around the time the radioactive seeds were stolen. A keycard is shown being used, except the doctor that the card belongs to is on vacation. Shockingly, a search shows that the card was used in the hospital—four minutes ago.

Nick tells Langston that Dr. Jekyll is on the fifth floor and radios the police to lock down the building. The CSIs give pursuit through the hospital, with Langston tracking Dr. Jekyll to a stairwell, then to the hospital's kitchen. Langston eventually ends up in a dark room lit by a light behind a red-tinted window. As he looks around for Dr. Jekyll, he's walloped on the head and knocked to the ground. Dr. Jekyll then stands over him and takes his CSI identification badge. Before Nick can get to the scene, Dr. Jekyll escapes out a nearby door. Langston continues to bleed and lose consciousness.


Main Cast[]

Guest Cast[]

  • Jorja Fox as Sara Sidle
  • Vincent Duvall as Lt. Jack Parker
  • Larry Sullivan as Officer Akers
  • Paula Francis as News Anchor
  • John Pyper-Ferguson as Dr. William Burke
  • Jack Conley as Jack Herson
  • Maurice Compte as Chalo Arua
  • Sierra McCormick as Gracie Layman
  • Jennifer Rhodes as Aunt Nellie Porter
  • Brady Smith as Tom Layman
  • Deborah Zoe as Lisa Layman
  • Maya Jezin as Younger Gracie


  • I'll See You In My Dreams by Joe Brown
  • Vide Cor Meum by The City of Prague Philharmonic Orchestra


  • John Pyper-Ferguson previously appeared in the series pilot as the unnamed husband.

See Also[]

CSI:Las Vegas Season 10
Family AffairGhost TownWorking StiffsCoup de GraceBloodsportDeath & The MaidenThe Lost GirlsLover's LanesAppendicitementBetter Off DeadSin City BlueLong BallInternal CombustionUnshockableNeverlandThe Panty SnifferIrradiatorField MiceWorld's EndTake My Life, Please!Lost & FoundDoctor WhoMeat Jekyll