Hayley Haller (b. 1997) is the daughter of Los Angeles prosecutor Margaret McPherson and criminal defense attorney Mickey Haller, the granddaughter of J. Michael Haller, the niece of LAPD detective Harry Bosch, and the cousin of Madeline Bosch. She also the niece of three unnamed aunts, and another unnamed uncle. In 2010 she met her cousin and they became friends. At this time her relationship with both of her parents was reasonably good despite their divorce. She wished that her father represented victims rather than criminals, but she saw him regularly on weekends and Wednesday evenings.
In early 2012. when she was 16 years of age, her father's client killed Sandy and Katie Patterson. Hayley decided that she did not want to see her father again. Katie Patterson had been her friend and Sandy had been her homeroom teacher. There was considerable press coverage about the case because her father was running for D.A. at the time. Hayley was forced to change schools, transferring to Skyline High School. She seemed to adjust well to the new school, making new friends and joining the soccer team. By 2013 her interest in soccer had faded and she became interested in horses. Her mother leased a horse for her, and she sent Haller a photo of Hayley on the horse.
By 2019, Hayley had graduated from Chapman College and was enrolled in law school at USC. When her father was accused of killing Sam Scales, she was frequently in court during the trial to show her support for her father. Originally, Hayley decided to follow her mother's footsteps into becoming a Prosecutor, but after her father was framed for killing his former client, Hayley decided to follow in her father's footsteps by becoming Criminal Defense Attorney. She also visited her cousin Maddie during her father's trial, while her uncle Harry is helping to defend her father.
On May 18, 2021, Hayley will be portrayed by newcomer Krista Warner in the upcoming "The Lincoln Lawyer" series for Netflix. The upcoming 10 episode series will explore the character’s close personal relationship with her parents, Mickey and Maggie.