The OG

Charlie uses math to determine the killer of an undercover FBI agent, and explores the endless interrelation of the killings so often simply written off as 'gang violence'.

Plot
At night somebody is driving through a neighborhood. Two leave Catch 21, a local restaurant. One is shot by somebody in the car.

At the Eppes’ house Don is watching the hockey game as Alan is about to leave on a date. He’s unsure of a gift to give his girlfriend, Donna, for her birthday. Charlie uses math to give Alan an idea. Don gets a call about the shooting and he leaves. At the scene David catches him up. LAPD have been told to wait to do anything until Lt Gary Walker of the Gang Impact Team arrives. The US Attorney’s office doesn’t want the locals to know that the FBI is on the scene so they have to keep things hush hush. The man killed was undercover FBI agent Anton Rhimes and they don’t want his cover blown. He was part of a multi-force task force and was undercover for 10 months before he was killed. He infiltrated the 23rd Street Syndicate. Don offers to talk to the AUSA. Megan and Colby think that his cover was blown and he was killed for it. AUSA Robin Brooks thinks they need to find out if his cover had been blown. Walker suggests hey bring everybody in for questioning, but Brooks stops that right away because that will guarantee that Rhimes’ cover is blown. Don agrees with her.

Brooks and Walker update the FBI team and Charlie. Charlie thinks he can help them with the investigation. There is surveillance footage from the restaurant that they finally get a hold of. Rhimes is with Travis Watts, a suspected shot called for the 23rd. Don suggests a warrant sweep, something that the police do regularly. Brooks gives it the green light.

Charlie is working with the data he received in the garage. Larry joins him and is overwhelmed by the fact that about 8,000 gang-related shootings have occurred in LA in the last four years. Charlie is keen to work out a way to deal with these crimes to bring justice for the victims.

The warrant sweep continues. David, Colby, and Walker approach a group of young, black guys playing basketball outside of a community center. One of the guys runs. David chases him into the gym at gun point where a man who is leading a group of children witness him cuff the guy. The community center director, Olivia Rawlings, asks if he’s got a warrant for this arrest. She says that maybe the guy’s running because of the fact that David had a gun. Walker asks if he needs any help and David tells her to let him do his job as he leads him out. The guy, Antony, has two outstanding warrants. David and Colby say they can overlook the warrants today if he tells them about Travis Watts.

They bring Watts in. Megan and David interrogate him. He suggests that the 23rds are retaliating for Rhimes’ death. Colby confirms that three drive-by's suspected of being done by the 23rds occurred not long before. Rhimes’ cover is intact. Why was he killed though? Hoover Park, a rival gang of the 23rds, is suspected of killing him.

Charlie has information for the team. He’s investigating shooting chains. He thinks he can track them back to the original shooting and therefore who did it. Walker is skeptical of Charlie’s methods. Megan talks to Rhimes’ wife. He hadn’t been home a lot the last few months so his death hasn't hit her. Megan asks her some questions about Anton. She could tell he was getting close to a breakthrough in the case. People were letting him into the inner circle.

At CalSci Charlie continues his work. Amita and Larry are helping him. Larry tells him to focus on one small question rather than a large, overarching question.

David goes to the community center and talks to John Owens, the man who was with the kids. He wants to see Olivia. They butt heads, but he wants her help to get witnesses to come forward. She’s wondering why there’s so much interest in this shooting over others. She doesn’t trust people just because they have a badge, so she is reluctant to help him. He leaves his card in case she changes her mind.

Don is going over the case in the dining room. Alan enters and they talk about the case. Charlie comes in with a breakthrough. He identifies 10 shooting chains and believes all of them were started by the same person, leading to over 60 murders.

At the FBI they are working on Charlie’s lead. Walker and Brooks are unsure. The shootings all targeted different gangs and used different weapons. On the surface they don’t see how they’re connected. Don tells them to start looking at the cases with fresh eyes. Megan finds that they were all single homicides, not a larger drive-by or something similar.

Megan follows up with Charlie, Amita, and Larry. She’s trying to figure out how the victims are being chosen. They started longer shooting chains than the rest. The shooter is trying to maximize retaliation which doesn’t make sense since his own gang could be targeted. Larry points out that the shooter may not be a gang member. Megan, David, and Colby talk about the case over dinner. Colby gets a call from ballistics. One of the guns used was turned in at a buyback program and should have been destroyed before the homicide occurred. A group of gang members and their friends are targeted by a drive-by. There are some fatalities and the FBI is called to the scene. David, Colby, and Walker are looking the scene over. It’s suspected that Hoover Park are the ones that shot them. One of the dead is Antony, the guy that ran from them earlier. Colby talks to David privately. The gun they identified as being tagged for destruction was signed for by Walker, casting suspicion on him.

Don and David talk to Walker about the buyback program. Colby interrupts. More than a dozen guns never made it to the furnaces to be melted down. Don gets Walker to take him through how the buyback program works. All of the guns were signed in at the same location because they were all approved by Walker. The location was the 23rd Community Centre. David goes to Olivia to get a list of the people who worked during the buyback event. She resists, but eventually gets the file. He gives them to Megan and Colby to connect to the first victim of the first shooting chain they're looking into.

Don walks into the Eppes’ house. He and Charlie chat about Alan’s date. He is home early (9:30pm). He informs them that he got her expensive soap and she wasn’t wowed by it. Alan notices how tired Don seems. Charlie suggests they look at the first chain rather than the first victim of the first chain.

The next morning Megan, David, and Colby are looking at the first chain. One of the victims in the chain was a man that killed a teenage boy, Ryan Owens who was the son of John Owens from the community center. John was at all of the buybacks. SWAT is called in to surround his house. Neighbors mention that they’ve seen him with a gun (possibly an AK-47). David says that he’s talked with John before and that he could try to get through to him. SWAT escorts him closer to the house and they talk. He lowers his gun from the window and stops talking to David. He has a pistol beside him and shoots himself with it.

Don is resting at his desk. Megan checks in on him. Don sent David home with Colby. Walker says that David did the best he could. Megan is on her way to talk to Rhimes’ widow. Don comes to the Eppes’ house. Alan is on his way to another date with Donna, bringing her theatre tickets instead of soap, and Charlie is on his way to a dinner with Amita and Larry. Don is left alone at the house and heads to the garage. He looks around at what Charlie has from the investigation including the victim photos. David is at the community center talking to the kids that John used to meet with.

Main

 * Rob Morrow as Don Eppes
 * David Krumholtz as Charlie Eppes
 * Judd Hirsch as Alan Eppes
 * Alimi Ballard as David Sinclair
 * Navi Rawat as Amita Ramanujan
 * Diane Farr as Megan Reeves
 * Peter MacNicol as Larry Fleinhardt

Recurring

 * Dylan Bruno as Colby Granger
 * Will Patton as Det. Gary Walker

Guest

 * Tamara Taylor as Olivia Rawlings
 * Michelle Nolden as AUSA Robin Brooks
 * Allan Louis as John Owens
 * Aldis Hodge as Travis Grant
 * Chastity Dotson as Karen Rhimes
 * Elijah Kelley as Anthony

Trivia
Tamara Taylor, who plays community center director Olivia Rawlings in this episode, went on to play Dr. Camille Saroyan in Bones; in that show she is head of the Forensic Division of the Jeffersonian and often works closely with the FBI to solve crimes. Aldis Hodge, who plays suspected shot caller Travis, went on to play Alec Hardison in Leverage; in that show he is a thief/hacker who, along with a team, works outside the law (usually) to solve crimes and right wrongs.

Music

 * "Remember the Name" by Fort Minor precedes the opening drive-by.

Goofs
After Charlie explains to Don why he should look at the entire first shooting chain Don says you'd be safe shooting "Tim" to start a chain that leads to the killing of "Bob" because you have no motive for killing "Tim". However you DO have a motive for killing "Tim", it's just that your motive is less visible.

Crazy Credits
[This appears at the beginning of the episode] 1,350 L.A. Street Gangs, 152,000 Gang members, 504 Homicides, 2.2 square miles