Internal Combustion
Season 10
Number 13
Writer Jennifer N. Levin
Director Brad Tanenbaum
Original Airdate February 4, 2010
Previous Episode: Long Ball
Next Episode: Unshockable

Internal Combustion is the thirteenth episode in Season Ten of CSI: Crime Scene Investigation.


The case of two high school students, one dead and one missing, lead the CSIs into the underbelly of streetcar racing and a tangled web of deadly competition.


Victims: Trevor Beck (deceased), Cindy Warner (missing)

On the case: entire team

The body of 17-year-old Trevor Beck lies on Doc Robbins' autopsy table. The only physical findings are bruises to the knuckles on Trevor's right hand consistent with a recent scuffle. Otherwise, Trevor shows no signs of trauma, disease, or abnormalities, nor are there signs of a cardiac event. Langston comes in to assist, and the two men watch Trevor's brain swell up when the cranium is opened. It's labeled as a massive cerebral edema, and Langston figures the injury occurred way before the fight Trevor had in school. Meanwhile, a flashback shows Trevor arriving at school, getting out of his car, and holding the back of his head. He makes his way through a crowd of students glaring at him; one of them has a black eye. When challenged to a fight in the school hallway, Trevor collapses and dies before any punches are thrown.

Trevor's mother tells Brass that she's unaware whether her son had suffered any recent injuries and notes that he had been irritable lately. She says that her son never fought and spent most of his free time working on his car, adding that Trevor had started seeing a girl in his class, Cindy Warner; the two spent some time together the night before.

The police are having trouble locating Cindy, as she wasn't at the apartment she shares with her brother. Archie triangulates the signal from her cell phone and discovers that it's coming from the high school. Sara heads to the school and finds out that Cindy wasn't in her homeroom that morning. She then talks to Renata Clarke, Cindy's best friend; the two share a locker together. Renata hasn't heard from Cindy, but figures she wanted to be alone after finding out that Trevor died. After Renata leaves to go to class, Sara finds an empty cell phone case in the locker.

In the parking lot, Nick processes Trevor's car, disappointed that the classic car has an electric motor. There's a fresh yellow paint scrape on the passenger's side door. Sara, now outside to help, finds an open packet of phenelzine, an antidepressant, and Cindy's cell phone in the pocket of the passenger's side door. Nick, meanwhile, plugs the car into a diagnostic module, which he says can log range, speed, and acceleration.

In the lab, Sara goes through Cindy's phone, including call log, photos, and emails. While there are several photos of Cindy with Trevor, there's also one of Cindy hugging another boy. The boy is eventually identified as Miyamoto Takahashi, and Sara finds a video of Trevor punching him in the face (which would explain the black eye the viewer saw in the beginning of the episode).

Brass finds Miyamoto at his after-school job in an auto parts store. Miyamoto, still sporting a black eye, watches the video and claims that he's the victim, something Brass rejects since Trevor is the one who died. He says that he used to date Cindy until she started going with Trevor instead. Brass believes the fight on video was about Cindy. Miyamoto is surprised to hear that Cindy is missing and insists that after the fight, he went to the store to help with inventory; the last time he saw Cindy was at the fight.

In the layout room, Langston tells the team that Trevor had a rare condition known as chiari malformation, a deformity of the skull that displaces the cerebellum and the brain stem into the spinal canal. He explains that most people don't even realize they have it until they've experienced some kind of trauma or vigorous neck flexion, such as a blow to the head. When it happens, the condition creates swelling, resulting in massive intracranial pressure and leading to headaches. Langston also notes that the phenelzine that was found would actually worsen Trevor's condition. The existing chiari, the medication, and the blow to the head helped create the perfect storm. Whoever gave Trevor the drugs was contributing to his death. Nick discovers that Trevor's car traveled 14 miles the night before his death, narrowing down the search radius to seven miles. This was also the last time Cindy was seen alive.

Cindy's body is eventually found mangled in a tree on the side of a road. She has compound fractures to both of her shins along with several internal injuries. Greg notes that there's no blood in the area, nor are they any footprints, indicating that this isn't a body dump. There are also no tire tracks and no evidence of another car even being on the road. In autopsy, Sara looks at Cindy's x-rays and sees that the injuries are consistent with being hit by a car. She tells Hodges that someone with Cindy's body type could fly the length of a football field if hit the right way by a fast-moving vehicle.

The team widens the search radius on the road, eventually finding the missing skirt from Cindy's cheerleading outfit, a flashlight, blood, yellow paint transfer, and tire marks. After processing the scene, Nick tells the team that he found two distinct tire marks, both originating in the same general vicinity. The yellow scrapes and blood on the road appear to be from Cindy's point of impact, which was roughly 1300 feet from the starting point. Cindy's body, meanwhile, was found 300 feet from where she was hit. With all of this evidence, Nick concludes that this was a drag race. One set of treads belongs to Trevor's car, while the other belongs to a still unidentified opponent driving a yellow car. The yellow paint from Cindy's wounds is a match to the yellow scrape on Trevor's door. This leads to the theory that one car swiped the other during the race; the collision caused the yellow car to lose control and strike Cindy.

Catherine tells the team that the phenelzine sold to Trevor came from a local pharmacy, and that the owner's son goes to the same high school as Trevor. The boy, Rishi Parayan, tells Catherine that he was giving the drugs to Trevor in exchange for help in their auto shop class. Rishi insists that Trevor didn't race and refuses to name anyone who might drive a yellow car—until he's told that the pills he gave Trevor helped contribute to his death. This means that Rishi's father could lose his store if found criminally liable. Rishi relents and says that the Demons, a local gang, use the color yellow.

A police-sanctioned drag race, the LVPD Street Rumble, is being held; Nick tells Sara that it helps keep racers off the streets—temporarily, at least. They find the yellow car in question, and a few members of the Demons are standing next to it. Sara notices that the bumper is banged up and that the car has the same color and tire size they've been looking for. The gang member says that he's watching the car for a friend, but conveniently doesn't know the name of that person. Just then, Miyamoto is spotted walking towards the car; he ends up getting arrested after trying to flee.

The car is brought into the CSI garage. While the wheel width, tires, and paint color match what was found at the scene, Greg tells Nick that he found headlight glass there, as well. Miyamoto's car has plastic headlights, meaning that they have the wrong car. Meanwhile, Sara realizes that a photo on Cindy's phone was taken at the LVPD Street Rumble and searches the website. Catherine and Sara watch a video that shows Trevor defeating Renata in a race; the car she was driving had yellow flames on the hood. Upon winning the race, Trevor came to a stop and suffered severe whiplash, leading Catherine to think that this caused his chiari; therefore, his death may have been an accident. The thought is that Trevor and Renata may have had a rematch in the desert.

At the high school, Nick and Sara talk to the auto shop teacher, Gus Davis, who is also Renata's uncle and legal guardian. He leads them to Renata's car, which she's working on. The CSIs look over the car and see no evidence of blood spatter or body damage; however, Nick notes that the headlights are glass and sees that the grill has been recently resprayed. They measure the wheel width and find that it matches what was found at the scene. Sara asks Renata why she called Cindy at 1:00 AM, and Renata replies that the late night calls were a regular occurrence. Renata is incensed at the notion that she killed her best friend and even more incensed when her car gets impounded.

In the CSI garage, Nick tasks Hodges and Wendy with finding any evidence that proves that this is the car that struck and killed Cindy. Hodges finds a piece of chewed up chewing gum under the steering column. Meanwhile, Sara tells Catherine that there are two ways to get to the drag where Cindy was killed, and that one way is en route from where Trevor and Renata live in Henderson. Sara goes to check to see if there's a traffic camera at one of the intersections. Elsewhere, Brass fills the police department in on the case, telling them that the Demons likely aided the driver of the car by chopping the parts of the car immediately after the incident. He tasks everyone with hitting up the known Demon chop shops and recovering any parts they can.

Several parts are able to be recovered, one of which is the original hood. Greg looks it over and notices an imprint on it; it matches the letters from the cheerleading sweater that Cindy was wearing when she was hit. He tells the rest of the team that there was so much kinetic energy transferred in the collision that when the fabric came into contact with the hood, it actually deformed the clear coat and the paint. No other prints are able to recovered from the parts. Greg wonders why Renata wouldn't just wait until the next LVPD Street Rumble to race Trevor again instead of racing him the desert. Catherine replies that the racer mentality runs in her family, as Gus was a stock car racer in the '70s. Sara intervenes and shows them traffic camera footage from the night of the incident—Renata was actually the one driving Trevor's car. So, if Trevor wasn't in the desert, who was Renata racing? Catherine peruses an article about Gus' racing days and notes that he used to put gum under the dashboard. She makes the connection.

Renata and Gus are interrogated together. Brass tells them about the chewing gum found in the car and assumes that it belongs to Gus. Gus tries to explain it away by saying that he and Renata work on the car all the time. Brass remembers that Trevor's mother said that the morning her son died, he thought he lost his car keys, only to find them in the car later on. He theorizes that Renata had Cindy steal the car and bring it out to the desert so she could race it. After Cindy was killed, Renata then drove the car back to Trevor's and left the keys inside the car. Gus denies everything, telling Brass that they're both leaving. However, when Brass lets Gus go and places Renata under arrest for felony murder, Gus comes clean.

A flashback shows him getting mad at Renata for losing the street race to Trevor, an amateur racer. Renata replied that Trevor's car was just better, but Gus tried to convince her that it's not the car that matters most, but the heart of the driver. He had Renata convince Cindy to steal the car so he could prove his point. The two raced in the desert. When Renata took the lead driving Trevor's car, Gus' competitive spirit took over and he tried to overtake Renata by bumping into her. This caused both cars to swerve and led to Gus eventually hitting Cindy, who was standing in the road. Gus admits that he sent Renata home and paid Miyamoto $500 to make the car look like new overnight. Brass asks the important question: who won the race?

Catherine relays the information that the district attorney is going to charge both Renata and Gus. Two lives have been ruined and two kids are dead—all for honor in a drag race.


Main Cast[]

Guest Cast[]


  • Stadtaffe by Peter Fox


  • Nick states that the Porsche is a 1958 Speedster and that James Dean had one just like it. James Dean died in 1955, so it's impossible for him to have owned a 1958 model. Dean's Porsche was a 1955 356 Speedster which was produced from 1948 thru 1955. The Speedster in the show was a 356A in production between 1956 and 1959.
  • In one scene, Brass is telling a group of uniformed officers to check for a 1933 Ford "Roadster". The photo behind him and the car being sought is a coupe. A roadster is an open car.
  • A close up of Cindy's legs and torso makes it very obvious it's a plastic doll in place of a real human being.
  • When Sara flips open Cindy's cell phone, it shows no notifications at all. Considering both her "BFF" and the Crime Lab had both tried to call her, there should at least be a notification showing the number of missed calls.


  • Nick Chinlund, who played the uncle Gus Davis in this episode, previously played ex-con Mickey Rutledge in the Season Three episode You've Got Male.
  • Brian George played Dr. Parayan, Rishi's father. He's perhaps most recognizable for his role as Babu Bhatt in the hit '90s show Seinfeld.

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