Brass and Grissom enter the house, and find the Klinefelds; Mr. Klinefeld is shot in the chest, Mrs. Klinefeld is shot in the back. Brass tells Grissom to get out while he secures the room, because Grissom doesn't have a gun with him. The house is empty. Grissom asks about two undercover officers outside, and Brass says that they've been there since the Judge Slater didn't sign the first warrant. Grissom comments that there's two undercover cops outside and two dead bodies inside.
Brass talks to the officers, who say that there was a call of an officer down, but they were unable to locate the officer. They left, and came back as soon as they could. Grissom wants their guns, and Brass insists that they turn them over, including their back-ups. Nick arrives with Warrick; Nick takes the inside; Warrick notes no signs of forced entry on the front door. Nick finds an unknown substance on the floor near Mr. Klinefeld, but doesn't know what it is. Grissom finds towels from The Sphere in the bathroom, and sheets from the motel in the dryer, all of which show blood. Warrick finds a footprint on a newspaper at the back door.
Brass talks to the undercover officers and tells them that there was a screw up; they don't care, and comment that there were no humans involved in the shooting. They comment that a kid across the street made them, and thought that they were bad news.
Catherine and Sara go to a house where college kids live, they go in and it's raining inside. An officer gives them an umbrella, the body is upstairs, in the bathtub, horribly bloated. O'Reily tells them that the roommates last saw the deceased on Thursday, before they went away for the weekend; they came back and found him dead. Catherine and Sara note that the water has washed away any evidence on the floor, but there might be something in the tub. They decide that the best way to get the body out of the house is through the window.
Warrick listens to the call of officer down. At the scene, Grissom uses the number that made the officer down call to find the cell phone, which is by a neighbor's house, near a puddle, which he swabs. Brass talks to the kid who made the undercover officers; he says that the two bad guys (the undercover officers) drove away, then a police officer walked up to the Klinefeld's front door and went in, but didn't come out. Brass comments to Grissom that there are no beat cops anywhere in Vegas except on the Strip.
Dr. Robbins finds trace evidence in the wound, and pulls out some of the same substance that was on the floor by Mr. Klinefeld's body. He asks if Mr. Klinefeld was shot through a window?
Catherine and Sara empty the tub; the drain is clogged, and Catherine notes that it was probably just an accident. They find no sign of a struggle, and no drugs in the medicine cabinet.
Nick tries to reassemble the pieces that he found near Mr. Klinefeld's body, and tells Warrick that the cell phone was traced back to a Public Defender. The results of the swab that Grissom took tell them that the liquid was soda, and the trace fragments that Nick found are polyethylene, which is a soda bottle. They decide that the shooter used a 'soda silencer.' The ballistic results don't match the officers' guns, or their back-ups. They decide that the shooter was watching both the Klinefeld's house and the undercover officers, made the false call of an officer down, and then when the officers left, went in and shot the Klinefelds. Grissom sends Greg out to look for the soda bottle.
Nick processes foot prints and compares them to shoes, but gets no matches. He then runs density levels to find out what the marking on the bottom of the shoe print is. Greg searches the streets for the soda bottle; he arrives at a backed up sewer drain, and looks down it.
Sara checks the victim's clothes and finds a number 7 backwards on the shirt, in red grease paint. She wonders how you get paint on the inside of your clothes and Catherine comments that it rubs off your chest, and a person with paint on their chest would be a sports freak.
Brass and Grissom argue over the case; Brass says that cops don't take the law into their own hands, but Grissom doesn't believe that, and says that he's just following the evidence. Greg arrives and tells them that he has something that they have to see; it's a police officer's shirt, with a badge on it, but he didn't find the bottle. Brass notes the tag on the shirt, and that it comes from the biggest uniform supplier in town. He also notes that there are buttons on the shirt, and that all the new ones have zippers; he runs the badge number to see if it's legitimate.
Dr. Robbins tells Sara and Catherine that the roommates couldn't make a positive identification, but he used dental records to get the name of the deceased: Daniel O'Hannissey. He notes that there was no water in his lungs, and that he died of a blow to the back of the head, which he suffered 12 to 24 hours before death. Catherine and Sara decide to work backwards from Thursday night.
Officer Fromansky tells Brass that he lost his badge years ago and filed a report at the time. Brass notes that Fromansky has a lot of entries in his file for excessive force; Fromansky says that any good cop does, and he does ~real~ work, unlike the paper pushers. Brass swabs his mouth for a DNA test to compare against the sweat on the shirt. Warrick listens to the 'officer down' call again, and comments that the caller is talking like a cop.
Sara and Catherine talk to Daniel's roommates, who say that he was a sports fan, and went to all the games. They comment that he was a real Bluto, and ruined the house the one time that he watched a game at home. They go to the bar that he watched the away games at, and talk to a waitress, who tells them that Daniel was there on Thursday night, and got into a fight with some other fans. She points out a couple of the guys who were involved in the fight.
Warrick gets a sample of Officer Fromansky's voice to compare against the 'officer down' call. Officer Fromansky stops Grissom as he's leaving and tells him that one day Grissom will need him and his buddies, and they won't be there for him. Warrick compares the voices, and they don't match; according to Archie, they're not even close. The lab has the DNA results as well, and the sweat doesn't match Fromansky's DNA.
Grissom tells Brass that he got ahead of the evidence and made it personal, and he doesn't know why. Brass says they both did, and it was kind of fun. Brass comments that a crime like this takes practice and then remembers a case where some gang-bangers walked, but were gunned down later by vigilantes. Grissom thinks it's an inside job, and Brass agrees, but doesn't think that it's the police. Grissom comments that if you take out the police, then who's left? Nick finishes his processing of the shoe prints, and finds that the mark on the bottom of the shoe is an imprint made by the seal at the court house. They go back to Judge Slater's chambers, and he tells them that if they want a warrant, they'd better have the evidence to back it up this time; but they tell him that they're not there to get a warrant, they're there to execute one.
Catherine talks to the guy from the bar, who says that he got in a fight with Daniel, and wants to know if Daniel ratted him out. He tells them that he didn't do anything, and when Daniel left, he was still running his mouth off, and seemed fine. Catherine notices that he's wearing a ring, and asks if she can see it; he gives it to her. It's a college ring, with a shark on it.
Grissom wants to see the shoes of the Judge, the Bailiff, and the Clerk. Brass tells the Judge that since the warrant came out of his office, those three are the only ones who knew about the Klinefelds. The Clerk's shoes have the imprint from the seal on them, from standing outside and stepping on his cigarette butts, burning his shoe.
Catherine tests the ring and points out that the fin is bent on the ring and it's because it hit something - Daniel's head. That guy in the bar sucker punched him from behind. Catherine and Sara tell him that even though Daniel walked away, he's still responsible for Daniel's death.
Brass interviews Stewart Gardner, the Judge's Clerk, who used to be a cop. He tells Brass that they're brothers; once a cop, always a cop. Brass says, "I'm not your brother. You're a murderer." He then goes over the crime, how Gardner waited outside, made the false call of an officer down to get rid of the undercover officers, and then went to the Klinefeld's and killed them. The DNA on the shirt matches him, and it's his old shirt from when he was an officer. Brass speculates that Gardner probably saw a lot of good cases get thrown out, working as the Judge's Clerk; Gardner asks Brass, "Doesn't it piss you off to put all your hard work in the hands of 12 people too stupid to get out of jury duty?" Warrick and Grissom watch the interview; Warrick says that Gardner is insane, but then admits to Grissom that he's thought about taking the law into his own hands, but never actually done it. He asks Grissom if he's thought about it; Grissom walks away without answering; as he walks down the hall, he passes Officer Fromansky, and looks back at him.
Grissom is at the shooting range, firing at a target. He finishes and brings the target up to inspect it; he's shot a perfect round.