Season 5
Number 17
Writer Josh Berman
Richard Catalani
Director Duane Clark
Original Airdate March 10, 2005
Previous Episode: Big Middle
Next Episode: Spark of Life

Compulsion is the seventeenth episode in Season Five of CSI: Crime Scene Investigation.


A budding serial killer strikes again, and the CSI team tries to use new technology to solve a cold case. Catherine and Nick investigate the murder of a young boy found dead in his bed. His brother confesses to the killing, but evidence suggests that he may not have committed the crime.


Victim: Martha Krell (deceased)

On the case: Gil Grissom, Greg Sanders, Sara Sidle, Jim Brass

Flight attendant Martha Krell checks into her room at the Four Aces Motel. As she goes to enter the room, someone attacks her and drags her inside. She's next seen on the bed in her underwear, stabbed to death. There are no signs of a struggle, and Brass sees that there's also no clothes or luggage present. The trashcan is also emptied, and the smell of bleaches and deodorizers fills the room. It seems that the killer attacked the victim, then cleaned and sanitized the room, leaving no trace of himself behind.

David Phillips puts Martha's time of death at ten hours before. He and Sara lay the body out straight to reveal that Martha has several defensive wounds and suffered at least a dozen stab wounds. In the bathroom, Grissom finds a clump of hair in the bathtub drain that tests positive for blood. He has Greg label it and sent it to DNA. Back in the room, Sara tells Grissom that hotel rooms are usually littered with prints; however, every surface has been wiped clean.

According to the front desk clerk who checked Martha in, she had been staying at the motel for a few months on a discount. When he called Martha to to relay a message to her that her A.M. flight had been canceled, she didn't answer. He went to her room, knocked on her door and again got no response. Using the master key, he entered the room to find Martha dead. When Brass is done questioning the clerk, the manager of the motel, Hayden Michaels, asks him to do everything possible to keep the crime out of the press, as it would be bad for business. Brass makes no assurances.

In autopsy, Doc Robbins tells Grissom that Martha's cause of death was exsanguination. She was also raped; a collection of sperm was recovered and sent to DNA for analysis. Meanwhile, Ecklie is going over a past case when Sara enters the room. Despite having paged Grissom, Ecklie fills her in on the case. Five years ago, the day shift worked the case of Sue Stein, a flight attendant who was raped and murdered in a hotel room. The scene is extremely similar to Martha's murder—Sue's clothes and suitcase were missing and the room smelled like disinfectant. The only difference, Ecklie says, is that Sue's room was on the first floor with an unlocked sliding door leading to the pool; however, Martha was murdered on the second floor with only one way in and out. Sue was also raped, and Ecklie is having Mia Dickerson compare the samples from that case and the current one. Sara notices that they were able to recover a fingerprint from the first scene; it's impressed in blood and the underlying pattern on the fabric made it impossible to read. However, Sara believes that modern technology can read the print now.

Mia tells Greg that the blood found on the hair in the drain is a match to Martha. Furthermore, the semen recovered is consistent with the semen recovered from the first attack; the same rapist has committed both murders. Under the microscope, they discover that the man's immune system doesn't recognize his own sperm and that the antibodies are attacking it. Both Greg and Mia recall an article they read that explains this phenomenon—the killer had a vasectomy, then had it reversed.

Lab tech Neil Jansen is able to digitally separate the bloody fingerprint from the fabric. The print is run through AFIS, and it comes back to a Jesse Acheson, who has multiple priors for cocaine possession. Sara confirms that Jesse was out of prison during both murders, and she, Brass and some uniformed officers visit Jesse's last known address. Jesse's wife Michelle answers the door and claims to not know where her husband is, adding that she hasn't seen him in days. After the conversation is over, Sara tells Brass and the officers to drive around the block and pick her up in five minutes. Sara peers through the window and watches Michelle call Jesse on the phone. In a one-sided conversation, Michelle tells Jesse that the cops were just at the house and she wants to know where he is. Jesse apparently hangs up on her, and Sara backs away from the window.

In the lab, Sara tells Grissom that she got a court order for Michelle's phone records and has been able to narrow down Jesse's approximate location. She had officers check registrations at the hotels in the targeted area and has found that Jesse is booked at the Tangiers. Greg enters and says that the rapist's semen came back positive for cocaine. They try figuring out Jesse's timeline, but find it odd that he would be dealing drugs out of one hotel, go to another hotel to rape and kill the victim, then head back to the first hotel to continue dealing.

A judge denies Grissom's request for a search warrant for Jesse's hotel room, saying that a five-year-old fingerprint "manipulated" on a computer isn't enough. She adds that if the print were later to be thrown out in court, then everything found as a result of it would be excluded and the rapist would go free. Grissom is told that he can get his warrant if he provides more evidence, but he tells the judge that he needs the warrant in order to get more evidence. Meanwhile, Greg and Officer Akers keep surveillance on Jesse at a café. When Jesse gets up and leaves his coffee cup behind, Greg collects it as evidence.

Mia tells Greg and Sara that there were two DNA contributions on the lip of the coffee cup, meaning that the coffee shop recycles, and "not in a good way." The worse news is that neither DNA contribution is a match to the semen recovered at the crime scene. Jesse is brought in for questioning and tells Sara that he doesn't know how his fingerprint ended up on the bedspread. He admits, though, that he went to see Sue the night she was murdered. When he entered her hotel room and tried to wake her up, he saw that she was covered in blood. A flashback shows him wiping his bloody hand on the bedspread and leaving. Since he was on probation, he didn't report the murder to the cops, believing that he would be the primary suspect. Jesse tells Sara and Brass that he and Sue had an arrangement—whenever she was in town, he would sell her drugs. The sliding door was left unlocked as a part of their arrangement.

Hodges pages Grissom to the trace lab and tells him that the hair pulled from the bathtub drain was coated in bleach, which compromised the trace. However, he adds that the bleach had a woodsy smell to it. Results of an analysis of the bleach indicate that it contains a cedar additive. Grissom admits that this is the first time that Hodges has impressed him.

Grissom and Brass speak to Hayden Michaels, who has offered to help out any way he can. With him is Lucy, the motel's head of housekeeping. She tells them that she started adding cedar chips to the bleach because guests were complaining of the bleach smell. The maids, who are all female, are the only ones with access to the bleach. Brass wonders if anyone walking by could've swiped the bleach, but Lucy says that all maids bring their carts into the rooms to prevent theft. While this is going on, Grissom looks at the photos on Hayden's desk. When questioned, Hayden confirms that he has been married more than once and has kids ranging from college-aged to a newborn. Grissom notes that Hayden must have had his vasectomy reversed; furthermore, he would also have had access to the bleach. Hayden is somewhat startled at the subject matter of these questions and refuses to give a DNA sample, as being labeled a murder suspect would put an end to his days working in hospitality.

Hayden is brought to the station for questioning, and Grissom tells him that during his 25 years on the job, he's come to understand the kind of person who's a rapist-killer. Grissom tells Hayden his theory about how the killer likely fantasized about the attack for years and gradually escalated closer to the actual event. After finally going through with it, he felt a level of excitement greater than what was anticipated. Grissom adds that what differentiates a psychopath from a "heat of the moment" killer is forethought. A flashback shows Hayden wiping down the hotel room with bleach. Grissom theorizes that Hayden was thinking about his crime for a long time. Hayden's lawyer says the evidence is circumstantial and they get up to leave.

Sara then enters with a wheeled luggage bag and claims that she has some evidence. An irate Hayden blurts out that she had no right to go into his car, and his lawyer says that no warrant was ever issued. Sara says that she was following a hunch and found out that the airline supplied this type of luggage bag to all of its flight attendants. Since Martha's bag wasn't in her room, she figured that the killer took it as a souvenir. Sara unzips the luggage bag to reveal a tape recorder. Now, the police know where to search to find Martha's luggage bag, while Hayden has just admitted to his guilt.

Victim: Ty Hawkins (deceased)

On the case: Catherine Willows, Nick Stokes, Warrick Brown, Chris Cavaliere

Catherine and Nick are called to a scene to investigate the murder of 12-year-old Ty Hawkins, who has been beaten to death while sleeping in his bed. David Phillips puts the time of death around midnight. There are no signs of forced entry, and nothing appears to be missing; there's also no murder weapon to be found. All of the windows and doors in the house were locked except for the screen door; Ty's parents claim that they locked that, as well.

Catherine processes the inside of the house, finding a baseball bat in Ty's bedroom that tests negative for blood. In the laundry room, she finds boxers, a fitted sheet and a t-shirt that all test positive for urine. Outside, Nick finds a shoe impression in the dirt outside of the bedroom window and casts it. The word "BRAT" is also etched into the window. As he walks around the property, he finds a pile of pipes and later notes to Catherine that one seems to be missing. He comments that whoever killed Ty knew how to get in and out of the house without disturbing anyone.

Nick and Det. Cavaliere question Ty's father, Martin. He says that he and his wife, Yvonne, went to bed after watching the news. He questions out loud why someone would do this to Ty and becomes angered when Nick starts to process him. Martin is fingerprinted and a DNA sample is taken before he and his wife are allowed to go home. However, their other son, 14-year-old Matt, is kept in police custody until the case is resolved. Nick asks Det. Cavaliere how he could just let the parents go home; he's told neither of them have a record or motive and that no blood was found on them. After Nick suggests that the parents could've showered and dumped their clothes, Det. Cavaliere says that, based on years of talking to grieving parents, he can tell their grief isn't an act.

In autopsy, Doc Robbins tells Catherine that the cause of death was blunt force trauma. Ty suffered 14 separate blows from a cylindrical weapon about one inch in diameter. Catherine asks if the weapon could be a pipe; the doc confirms this, showing her that one of the wounds contains a thread pattern that's consistent with the end of a pipe. Ty also has no defensive wounds, and Doc Robbins guesses that he never woke up during the attack.

Matt Hawkins sits in interrogation and hands over his shoes. Det. Cavaliere goes full court press on Matt, accusing him of murder. He gets in Matt's face and yells at him, telling him he's going to prison. Det. Cavaliere gets angrier as Matt remains silent and looks at Nick. Nick interrupts and asks to speak to Det. Cavaliere outside. He tells him that they don't have enough evidence to suggest that Matt is the killer, as there was no blood on his clothes and the intruder could've entered through the screen door. Instead, Nick suggests they ask different questions or take a different approach. Det. Cavaliere takes offense and says to Nick that he doesn't tell him how to do his job. Nick insists that they're all on the same team, but the detective wants him to find evidence to use against Matt.

Catherine processes Ty's t-shirt and finds a hair and some blue fibers on it. She later confirms that the hair is consistent with Matt. Meanwhile, Nick compares everyone's shoes with the print found outside of the bedroom window; the print is also a match to Matt. He tells Catherine that these could be findings important to the case, or they can just be the result of two brothers living together. The blue fibers are currently unexplained, as nobody in the family was wearing blue at the time they were brought in for questioning. Nick shares his concern with Catherine about Det. Cavaliere getting ahead of the forensics, but she says that the district attorney won't file without any physical evidence.

Nick visits Det. Cavaliere and tells him that, with no definitive evidence, Matt can't be held in custody for more than 24 hours. Det. Cavaliere shows him a signed confession from Matt and says that he caught him lying on a voice stress analyzer. Once the lie was caught, Matt confessed to murdering his brother. Nick tells him that the device has been discredited for years and isn't used in Vegas or in the state of Nevada. Det. Cavaliere admits that Matt's parents or an advocate weren't present at the time of the confession, but as long as Matt understands his rights, nobody needs to be there with him. Matt hasn't said why he killed his brother, but Det. Cavaliere is sure he will eventually. He thanks Nick for helping out and insists that the police can handle it from there.

Warrick, fresh off of testifying in court, was filled in on the case. He was told by the district attorney that Matt's confession would hold up in court; however, Nick is still uncertain about Matt's guilt, believing that Det. Cavaliere intimidated him into confessing. Furthermore, there have been some disturbance calls in the Hawkins' neighborhood about a homeless guy running around peeping in windows and urinating in public. There were also a few attempted breaking and entering incidents. Nick says he's going back to talk to the family, and Warrick offers to tag along.

Martin and Yvonne Hawkins are shocked when told that Matt is under investigation, adding that the boy doesn't handle stress well. They also confirm that Matt's clothes were the ones Catherine found in the washing machine earlier. Nick and Warrick ask about the homeless man; they're told that he scared the two boys a few times, and that Ty caught him writing something on the window. Nick confirms that the word "brat" is what was written. Matt then cleaned it afterwards, which would explain why his shoe impression was found outside of the bedroom window. Martin tells them that he jogs in the park every evening and that the homeless guy has a makeshift tent set up there. Nick, Warrick and some uniformed officers head to the park and find the homeless guy asleep in the tent. The man is dragged out and reveals that his name is Walter. He's wearing a blue sweater with blood stains on it; when asked, he doesn't say where he got it. Walter is arrested for suspicion of murder and brought in for questioning. The blood on the sweater is later confirmed to be Ty's.

Det. Cavaliere stops Nick in the hallway and asks him why he continues to meddle in the case. Nick insists that he's just following the evidence and convinces him to interrogate Walter. Walter admits to having found the bloody sweater on a bench in the park, but can't recall exactly when he found it. As Walter is taken away to be put in lockup, Det. Cavaliere tells Nick that he has a signed confession, while Nick has a homeless guy in a sweater. Clearly, Nick needs more evidence.

Nick processes the sweater and, using the UV light, finds an invisible dry cleaner ID stamp. He called the dry cleaners and found out that the sweater belongs to Martin Hawkins. Martin confirms to Nick that it's his sweater; however, he says he hasn't seen it in a while. Nick informs him that his son's blood is on the sweater, and Martin asks if he's going to need a lawyer.

Catherine, Nick and Warrick go over the three suspects and scenarios they have: 1) Matt wore his father's sweater, killed Ty, and dumped the sweater in the park at night, 2) Martin killed his son while wearing the sweater and later dumped it in the park, or 3) the sweater could've been accidentally left in the park where Walter found it, broke into the house through the screen door, and killed Matt. However, none of the evidence points towards a motive. Catherine asks what each suspect's height is and tells Nick and Warrick to meet her in the garage later for an experiment.

Catherine notes that Warrick is about Martin's height and Nick is about Walter's height. Judy, the receptionist, is brought in because she's about the same height as Matt. A dummy covered in red dye is elevated off the ground at the same height Matt's bed was. Wearing white sweaters, all three take whacks at the dummy with a pipe to recreate the blood spatter pattern. When the carnage is over, the blood spatter on Judy's sweater is similar to the one on the blue sweater.

Back in interrogation, Matt tells Nick and Det. Cavaliere that he already confessed and refuses to say why he killed his brother. Warrick, watching from behind the glass, lets Martin enter the room to talk to his son. There, Matt admits that he got mad at Ty for telling everyone that he wet the bed. Matt is arrested and taken away in handcuffs. When Det. Cavaliere demands an apology from Nick, Nick has a simple reply: "I'm sorry...that you feel that way."


Main Cast[]

Guest Cast[]


Detective Cavalier: You owe me an apology.
Nick: I'm sorry... (pause) that you feel that way.


  • Just after the opening credits, when Greg hands Grissom the "Phillips" screwdriver in the bathroom, it's clearly A) not a Phillips bit and B) not the same head that Grissom uses to unscrew the drain cover.
  • Since Catherine is the head of the swing shift (4:00 PM-12:00 AM), there's no valid reason for her getting a case that begins at the crack of dawn.
  • When Greg collects the suspect's discarded coffee cup from the table at the café, he isn't wearing any gloves which would've contaminated the DNA evidence.
  • About the middle of the episode, when Nick and Warrick are interviewing the couple in their living room, on the right side of the room you can see a crew member moving behind the glass doors.
  • Near the end of the episode, the CSIs verify a blood spray pattern by hitting a dummy with a pipe. When Nick takes his turn, we first see a side-on shot where the upper half of his sweater is spattered liberally with blood. The camera then cuts to a head-on shot, where Nick's sweater suddenly has significantly less blood on it.
  • When we are shown the flashback of Matt killing Ty, you can see sunlight coming through the window. However, when the CSI team is looking over Ty's body, they say his time of death was around midnight, so there should've been darkness coming from the window.


  • I've Been Waiting for You by Constanza


  • Michaels' murder sofa flight attendants are inspired by two infamous murders of flight attendants, with amalgamations of the details: the unrelated murder of Susan Taraskiewicz and Wanda Jean Wadle.
  • Jason Segel, who plays lab tech Neil Jansen, is most famous for his role as Marshall Eriksen on How I Met Your Mother.
  • The character of Walter was played by Wil Wheaton. Wheaton is most known for his television roles in Star Trek: The Next Generation and The Big Bang Theory, as well his role in the movie Stand By Me.
  • Stephen Baldwin played Jesse Acheson in this episode. The youngest of the four Baldwin brothers (Alec, Daniel and William are the other three), he's an accomplished actor with over 100 film and television credits to his name.

See Also[]

CSI:Las Vegas Season 5
Viva Las VegasDown the DrainHarvestCrow's FeetSwap MeetWhat's Eating Gilbert Grissom?FormalitiesCh-Ch-ChangesMea CulpaNo Humans InvolvedWho Shot Sherlock?SnakesNesting DollsUnbearableKing BabyBig MiddleCompulsionSpark of Life4 x 4Hollywood BrassCommittedWeeping WillowsIcedGrave Danger, Part 1Grave Danger, Part 2