Mea Culpa
Season 5
Number 9
Writer Josh Berman
Carol Mendelsohn
Director David Grossman
Original Airdate November 25, 2004
Previous Episode: Ch-Ch-Changes
Next Episode: No Humans Involved

Mea Culpa is the ninth episode in Season Five of CSI: Crime Scene Investigation.


When an unknown fingerprint suddenly appears on a piece of evidence in court, Grissom must re-open the case and find the real culprit. However, this unexplained phenomenon causes Ecklie to doubt Grissom's handling of the case. Ecklie then opens an inquiry on Grissom and questions each of the CSIs about his effectiveness as supervisor. Meanwhile, Greg and Sara investigate the circumstances surrounding the death of a man who shot himself in the leg.


Victim: Max Larson (deceased)

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

Grissom is on the stand in court recounting the events of a murder from 1999, where Max Larson was found beaten to death with a wrench inside his hardware store. The wrench was found in a toolbox underneath a sink at the restaurant next door, and it had the defendant's fingerprints on it. The victim's blood was also in the grooves of the wrench. The defendant, Jason Garbett, also tried to set a fire with a book of matches, but was unsuccessful in doing so. Grissom is then shown the matchbook, which is still in its sealed evidence bag. He confirms that it was the matchbook found at the scene, but notices a fingerprint that wasn't there before. After requesting a recess, he privately tells the prosecutor that the print on the matchbook doesn't match Jason's prints that they have on file. Grissom realizes that he has just given the defense reasonable doubt.

Back at the lab, Grissom is stopped by Conrad Ecklie, his new supervisor. Ecklie wonders how Grissom missed the fingerprint and asks if the matchbook could've been switched out. Grissom tells him that the evidence seal wasn't broken; therefore, it isn't possible. Ecklie responds by telling Grissom that he's opening up a supervisory inquiry. They're interrupted by the sound of a gunshot and a window breaking. In the ballistics lab, Bobby Dawson tells Ecklie that he was getting ready to test fire a gun when it accidentally discharged. The gun is from a case Greg and Sara are working.

Catherine, Nick and Warrick tell Grissom that they all remember the case—the Garbetts owned the restaurant next door to the hardware store, but Max Larson owned the alleyway behind both stores. Max had blocked the alleyway with dumpsters because he felt that the restaurant's deliveries were clogging up the area. The Garbetts sued to have the dumpsters removed and lost. Because of this, they couldn't get deliveries and the restaurant's business dried up. In addition, Jason Garbett had an argument with Max the day before Max was killed. Grissom tells them that the evidence has been brought into question and that the fingerprint on the matchbook doesn't match Jason. He assigns Nick and Warrick to the case and puts Catherine in charge, telling them that he can't work the case.

Catherine, Nick and Warrick go over the old evidence from the case. Hairs were found near the victim, but never processed by DNA; Warrick says that the district attorney had enough evidence and filed charges before he could do anything with them. Nick found six fingerprints on the wrench, with five of them matching Jason and one of them being unidentified. At the time, the print was deemed irrelevant because the wrench was found in a common area. Catherine has Nick run the unidentified print and compare it with the print from the matchbook.

The unknown print from the wrench matches the print recovered from the matchbook, meaning that someone other than Jason touched both items. Jason's ex-wife, Mrs. Garbett-Katz, voluntarily comes to the station and talks to Nick. She tells Nick that Jason hardly ever raised his voice when they were married, but when he did, the whole neighborhood knew it. Her son Keith enters and asks how he can help; Nick asks him for a list of anyone who had access to the restaurant five years before. Jason is interested that new evidence has turned up in his father's case, and his mother tells Nick that Jason has always believed in his father's innocence and has done everything to try get him freed from jail. This includes moving back to Vegas, and Jason tells Nick that he was living in Los Angeles at the time of the murder. Mrs. Garbett-Katz says she has some old records at the house and will send them over to the lab.

Lab tech Mia Dickerson tells Warrick that the hairs recovered from the original crime scene weren't human and that she sent them to David Hodges in trace. Meanwhile, Grissom runs an experiment, testing to see how ninhydrin (which he used in the original case) reacts to his fingerprints. He's interrupted by Ecklie and the prosecutor. The prosecutor is concerned, as he has heard that the lab has reopened the case and he has been summoned to the judge's chambers in the morning. Ecklie tells Grissom that he's making the lab look bad, and Grissom can't answer the question as to whether they've arrested the wrong guy.

Under a microscope, Hodges compares the hair from the crime scene with a human hair. They're clearly not a match, and Hodges concludes that the hair is canine and is from either a poodle or a Portuguese water dog. Catherine enters and wonders why Warrick is in trace; he fills her in, then says that he'll go find out if the victim or suspect owned a dog. Hodges, meanwhile, reveals to Catherine that he told Ecklie about the hairs and that he and Ecklie are "friends."

Nick tells Catherine that the restaurant employed six waiters, two cooks, and a busboy—all of whom would've had access to the kitchen and the wrench. The prints for Mrs. Garbett-Katz, three waiters, and both cooks are all on file, and none of them match the print in question. He's able to find out everyone else's address through their social security numbers, tracks them down, and takes their prints; however, he later finds these are also no match to the matchbook or wrench. Meanwhile, Warrick speaks to Max's former business partner, Rich Reeba. Rich tells him neither he nor Max owned a dog and that Max didn't allow them in the store. He's quite unhappy that the case has been reopened and maintains that Jason killed Max over their dispute with the dumpsters and the alleyway; in fact, he was present when Jason tried to shake Max down. Warrick confirms that Max and Rich were joint owners of the property and that, when Max died, Rich got it all. Rich doesn't appreciate the insinuation.

In the lab, Catherine runs video spectral analysis on the matchbook to see if she can bring out an image on it, something that wasn't possible five years ago. They eventually find that the matchbook is from a club called PCH in Los Angeles. Nick finds this interesting since Keith used to live there. He and Brass go to visit Keith and, on the way up to the house, Brass tells Nick that Keith used to work as a veterinarian. Nick brings up the dog hairs found at the crime scene that were out of context at the time. They speak to Keith, who confirms that he spent some time at Club PCH in his clubbing days. He's taken aback when asked if he could provide his fingerprints and refuses to do so, ending the conversation quickly. Noting that trash on the curb is public property, Nick takes a garbage bag back to the lab without the need of a warrant.

Grissom speaks to lab tech and fingerprint expert Neil Jansen and asks for his expertise. Neil tells him that since fresh fingerprints have fewer amino acids and n-termini, it could take a fingerprint months or even years to appear after being sprayed with ninhydrin. Based on the fact that the matchbook was in a plastic bag for years, it's quite possible that the bag was acting as a humidifying chamber and that the print was being processed in slow motion.

Nick processes the garbage bag from Keith's house and gets some prints; the prints match the unknown print from the matchbook. A flashback shows Keith entering the hardware store with a wrench and beating Max Larson to death. In the interrogation room, Catherine and Nick tell Keith that he lied to them. Despite saying he was living in Los Angeles, he was in Vegas at the time of the murder, running the restaurant while his parents were in court suing to have the dumpsters removed. They have evidence from the records provided by Mrs. Garbett-Katz that show that Keith signed the vendor checks the week of the murder. Catherine and Nick tell Keith's lawyer that both Keith and his father can be tried for the same crime; at minimum, they're looking at conspiracy to murder. After a little while, Keith admits that his father had nothing to do with Max's murder. He admits to keeping quiet because he never thought the courts would convict an innocent man. Grissom and Ecklie are watching this exchange from the observation room. Despite the case being solved correctly this time, Ecklie still wants to talk to Grissom in his office.

Victim: Paul Turlock (deceased)

On the case: Greg Sanders, Sara Sidle, Louis Vartann

In the morgue, Greg and Sara visit the body of a John Doe who died from a single bullet wound to the leg. The gun used was the same gun that accidentally discharged on Bobby Dawson in the ballistics lab. Sara glances down and sees that the victim has a tattoo on his arm that says "Rita." Greg says that the victim's jeans tested positive for gunshot residue around the entrance hole; Sara hypothesizes that either someone shot the victim at close range and left the gun behind, or the victim shot himself. Since most suicides are through the torso or head, it's looking like the shooting was accidental. It's determined that the bullet trajectory is up to down, which is also consistent with a self-inflicted, accidental injury. The victim didn't have a wallet on him and nothing came back on his fingerprints, so he's ruled a John Doe for the time being.

Bobby tells Sara that he figured out what made the gun accidentally discharge. It turns out that someone tried to turn the gun into a machine gun by grinding the trip down, which prevents the bolt from locking back. Sara guesses that the victim never even pulled the trigger and that he had the gun accidentally discharge on him, as well. The serial number on the gun has also been ground down, presenting Sara with a challenge.

Greg and Sara process the gun and are unsure whether the deceased bought an already modified gun or whether he modified himself and tried to sell it. Sara wonders whether the victim modified the gun for his own use, but Greg astutely asks why the serial number would need to be filed down if that were the case. She uses different compounds to make the serial number visible and has Greg run the number through the NCIC.

It's discovered that the gun is registered to Paul Turlock, and Greg and Sara meet Det. Vartann at Paul's residence. A pile of newspapers stacked up against the front door seems to confirm that Paul is their John Doe. There's nobody inside the house, but Greg uncovers a box containing five mac-10's with their serial numbers obliterated. Files and grinding stone are also present; both are needed convert a semi into an automatic. Vartann finds a picture of two guys, and Sara recognizes Paul because of the "Rita" tattoo on his arm. There are two messages on Paul's answering machine. The caller told Paul that he was interested in buying the modified guns and set up a time and place to make the deal. Vartann guesses that the deal would go down in the same place where Paul showed the buyers the prototype. The time set is for 9:00 PM that night, and they figure they've lucked out because the buyers don't know Paul is dead.

A man drives into the open field where the original meeting occurred; when he gets out of the car, he's surrounded by the police. As Vartann points his gun at the man, the man responds that he's an undercover ATF agent. This story is corroborated by other agents that arrive shortly after. The ATF was going to bust Paul for his illegal dealing of firearms; however, Sara tells them that Paul accidentally killed himself four days earlier.

During the cases, Ecklie looks into the backgrounds of the CSIs and questions Grissom's leadership style, while Sofia has been assigned to Grissom's inquiry due to her being the lab's Quality Control Officer. Brass warns Grissom that since Sofia has been assigned to the inquiry, she will tell Ecklie what he wants to hear in order to keep her job as acting day shift supervisor. Ecklie's findings:

- He talks to Warrick about his gambling problem; Warrick responds that that's in the past and that Grissom helped him get through it by being a friend. However, Warrick admits that he was never privy to departmental resources to help him with his problem.

- He asks Catherine about the Max Larson case and she's unable to confirm whether Grissom conducted a supervisory review after the case. She wonders aloud if Ecklie is doing these reviews for the sake of the lab or to indict Grissom; he replies that he just wants to make sure the right people are in the right place. Catherine brings up her application for day shift supervisor and Ecklie makes a snarky comment when the subject of money is brought up. She leaves his office without being formally excused.

- He asks Sara whether she finished up with her Police Employee Assistance Program (PEAP) counselor due to her alcohol problem. She takes offense to this question and tells Ecklie that it's none of his business; however, Ecklie can make it his business thanks to his new position. He notes that Grissom didn't make a note of their conversations in her file regarding her completion of the program.

- He commends Nick for a job well done on the Larson case (along with a past case), but wryly adds that despite Nick's independence and proficiency, Grissom didn't provide him with other CSIs as a support staff.

At the end of the episode, Ecklie has Grissom and Sofia in his office. Sofia gives her report and, much to Ecklie's surprise, says that Grissom didn't violate any procedures during the Larson case—he followed laboratory protocol and when he found that the evidence didn't correspond to his records, he notified the D.A. and recused himself from the case. This clearly doesn't sit well with Ecklie, as he was expecting Sofia to be on his side. Ecklie brings up his perceptions of Grissom's inability to supervise, which seems to be outside the scope of the inquiry.

Ecklie tells Grissom that he's breaking up the team. He promotes Catherine to swing shift supervisor, despite her application to be a day shift supervisor (swing shifts start at 4:00 PM). The old swing shift supervisor will be transitioned to the day shift supervisor, a role Sofia had for the last month. Nick and Warrick will be on the swing shift and report to Catherine, while Greg, Sara and Sofia will report to Grissom for the graveyard shift. Sofia, in essence, has been demoted thanks to her favorable review of Grissom.


Main Cast[]

Guest Cast[]

Major Events[]

  • As a result of his investigation into Grissom, Ecklie decides to split up the team. He gives Catherine the position of swing shift supervisor, assigning Nick and Warrick to her team. Grissom remains supervisor of the night shift and gets Sara and Greg along with Sofia.


  • Ecklie checks into the backgrounds of the various CSIs and notes Warrick's gambling problem (a storyline in Season 1), Sara's drinking problem (she got pulled over for a DUI at the end of Bloodlines), and Nick's success with the Westonson case (Eleven Angry Jurors).


  • Jason Segel, who plays lab tech Neil Jansen, is most famous for his role as Marshall Eriksen on How I Met Your Mother.
  • Science fiction fans might recognize Nana Visitor, who plays Mrs. Garbett-Katz, for her role as Colonel Kira in Star Trek: Deep Space Nine.

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