It stars Titus Welliver as Harry Bosch, who's now doing private detective work after leaving the LAPD, Madison Lintz as Madeline "Maddie" Bosch, Harry's daughter and now rookie LAPD officer based from the Hollywood Station and Mimi Rogers as Honey Chandler, defense attorney who decided to defend a homeless man accused of murder by the LAPD. It adapts plot threads from Michael Connelly novels The Night Fire, Dark Sacred Night, The Wrong Side of Goodbye, and The Crossing

In the first season, the Bosches work the street on their respective sides with Harry being recruited by Honey help look into a case that could involve The Mafiya while checking on a case for a recluse aerospace businessman millionaire on whether he had a child out of wedlock that he wasn’t made aware of. Maddie gets into patrol shifts, working with various experienced officers and encounter various realities in the streets of LA.

The second season shows Harry and Honey investigating the murder of a sheriff's deputy's wife and trying to clear the latter's client, who has been implicated in the murder despite his protests that he and the victim never even met, while also fending off an investigation by the FBI, who look to implicate them in the explosion of Carl Rogers' pipeline and his murder by the Bratva from the previous season. Meanwhile, Maddie works to recover from the trauma of her abduction and joins a community policing unit along with her old training officer.

The show was renewed for another season prior to the first season being streamed online. The second season started streaming on October 20, 2023.

It was also renewed for the third season before the fall premiere of the second season.

This series provides examples of:

• Bavarian Fire Drill: Bosch gets out of being shot by armed security in an oil refinery used by Carl Rogers by using Creighton's business card to pose as a Trident Security officer doing a surprise audit.
• The Cameo:
  • Most of the cast of Bosch does not appear as Amazon basically worked that show into Bosch: Legacy as a cost-cutting move. But Jamie Hector makes a few appearances as Jerry Edgar. In season 1, Bosch turns to Jerry to stash some sensitive information from the Whitney Vance investigation. In the first two episodes of season 2, he and Joan Bennett oversee the investigation into Maddie's abduction.
  • The second season features more cameo appearances from members of the Bosch cast. DaJuan Johnson and Jacqueline Obradors reprise their roles as Rondell Pierce and Christina Vega, and are handling the police investigation into James Allen's murder. While in the season finale, Lance Reddick makes a posthumous cameo as Irvin Irving, when Honey asks him to endorse her campaign to be district attorney.
• Clear My Name: Honey decides to take the case of Jeffrey Herstadt, a homeless man the LAPD are trying hard to paint as responsible for the stabbing death of a respected doctor.
• Crime After Crime: Paired with Revealing Cover Up. These are the motivations of corrupt vice detectives Don Ellis and Kevin Long in season 2, with them having been using their positions to run a prostitution entrapment ring: they have prostitutes entrap wealthy men in compromising positions, take video and photos of the encounter, and threaten to release them to the public and ruin the men's professional and personal lives unless they pay up. One such victim is Dr. George Schubert, who pays them with jewelry, including a watch, due to not having the cash due to gambling issues. The detectives then sell the jewelry to Paul and Peter Nguyen, who run a jewelry store that doesn't ask too many questions. Eventually, Vince Harrick, an LA County Sheriff's Deputy, buys said watch for his wife, Lexi Parks, an assistant city manager, as a Christmas present. Everything is fine until the watch breaks, and when Lexi calls the brand's service center to get it fixed, she discovers that it has been reported stolen (by Schubert's wife, from whom he concealed his troubles). She calls the Nguyen brothers to get an explanation (as possessing stolen property could put her and her husband in legal trouble), and when they repeatedly give her the run-around, she threatens to open an official inquiry into their business practices. Ellis and Long soon get wind of this and, realizing that an official inquiry will eventually lead back to and expose them and their entrapment/extortion scheme, decide they have to get rid of Lexi. However, they also realize that simply murdering her will only bring more questions and investigation unless they serve up a patsy to close the case. To that end, they force their confidential informant James Allen, a male prostitute and drug dealer to collect DNA from his secret lover/client David Foster after a meet-up. They then break into Lexi's home at night, murder her, plant Foster's stolen DNA both all over and inside her to frame him for her rape and murder, and then murder Allen to both cover their tracks and leave Foster with no way of confirming his alibi (that he was meeting Foster for another rendezvous). When Bosch and Chandler begin digging into the truth, Ellis and Long do everything possible to interfere with their investigation: they perform an unwarranted traffic stop and arrest Honey on false charges in order to get into her files on the case, put a tracker on Bosch's car and follow him all over town, murder the Nguyen brothers and steal and destroy their security footage to cover their tracks again, try cozying up to Maddie to see what she knows, and eventually try to run Bosch off the road. It all comes to a head in a shootout at Dr. Schubert's home between Bosch and the two detectives, in which the doctor is killed, Long is wounded, and Ellis escapes, goes on the run and is eventually killed by Maddie after a final confrontation with her father.
• "Friends" Rent Control: In "Inside Man", Bosch is seen at his LA house overlooking the cliff, trying to get repairs in place to make it safe from earthquake damage. It's hinted from the episode that he still lives there if he's not busy.
• Jury and Witness Tampering: The show opens with Carl Rogers getting off on a mistrial after the Russian mobsters he's affiliated with intimidate Willy Datz (the Vegas mobster who hired the hitman that killed Franzen, Franzen's mistress, Fowkkes, and Judge Sobel, and attempted to kill Chandler and Maddie) into recanting his testimony.
• Morton's Fork: At the end of "Plan B", Chandler offers Rogers one. As his plan to steal more gas to pay back the Bratva has been stopped by Bosch, he can either turn himself in for everything he did in the previous series, or be killed by the Bratva for failing to repay them. Rogers tries to Take a Third Option, but it fails.
• Mythology Gag:
  • "Plan B" has Harry mention the tunnels in Tora Bora where he'd previously encountered planted explosives, after infiltrating the Drysdale oil refinery.
  • "Chain of Authenticity" has Honey telling the California Attorney General that she has the scars to prove it, referring back to the attempt on her life carried out by Charles Kipps on orders from Carl Rogers.
  • "Zzyzx" has Maddie meeting with Coltrane. He happens to be the dog used by Amazon to promote the show online.
• Police Procedural: The genre centers on Maddie as she learns the ropes of being an LAPD officer by learning what it’s like from various training officers.
• Private Intelligence Agency: Trident Security eavesdrop on Harry after his initial meeting with Whitney Vance of Advance Engineering via aerial drones despite the fact that TS arranged for the meeting.
• Spotting the Thread: How Bosch figures out Ida is behind almost everything. His first clue is the realization that Whitney Vance couldn't have written the amended will because he personally saw the man barely able to handle a pen writing his name to a check. He then has Ida sign a fake affidavit and it'll be a snap comparing the handwriting to discover Ida wrote the will on Vance's orders, then forged his signature at the end.
• Surprisingly Realistic Outcome: When Los Angeles is hit by a minor tremor in "The Wrong Side of Goodbye", some cracks appear on some parts of Harry's house. He is warned by an inspector that he needs to look at the foundations or have his house torn down and reconstructed.
• Tracking Device: Season 2 has a tracker installed on Harry's SUV by corrupt LAPD detective Don Ellis and Kevin Long. When Mo asks him about getting rid of it, Harry tells him not to so that he can fool them during their surveillance ops.
• Two Lines, No Waiting: While Harry is involved with various PI cases and hired by various clients (including Honey), Maddie works through the LAPD and tries to be an officer the force can count on while having the legacy of being the daughter of parents who have careers in law enforcement and also struggles with the various cases that she encounters as a uniformed officer.
• Wham Episode:
  • In "Always/All Ways", Harry races to Maddie's apartment to see signs of someone breaking into her apartment by destroying the mesh screen.
  • In "Inside Man", Chandler was visited by FBI agents for an investigation into Roger's death as a potential witness. At the same time, Maddie's seen packing a gun for self-defense before she goes to sleep.
  • "A Step Ahead" has Chandler announcing plans to run for Los Angeles County District Attorney. Maddie got a phone call from Preston Borders. He told her that he "took care of it". Maddie presses Harry on what it means.