The presence of Mickey Haller's father in The Lincoln Lawyer is a major change from the books that the series is based on. Mickey Haller, Sr. appears in a flashback in The Lincoln Lawyer episode 6. The senior Haller was a celebrity attorney and served as the eponymous Lincoln lawyer's hero and inspiration.
In the flashback, Haller watches his father win a case that makes a lasting impression on him as a young boy. However, this flashback never takes place in the book. In fact, because of a key detail, it would be impossible and a major change was necessary to be able to show it.
Related: Elliott Gould Cameo Allows For A Lincoln Lawyer Season 2 Book Change
The Lincoln Lawyer season 1 is based on The Brass Verdict, the second book in Michael Connelly's The Lincoln Lawyer series. In the books, Mickey Haller, Sr. died much earlier, when Mickey Haller Jr. was only five. At this age, Mickey would not have been old enough to have witnessed his father practice law and to have the conversations that are shown. Because of his father's death when Mickey was still young, he instead gets to know about his father and learn about his profession by reading about him. This change impacts The Lincoln Lawyer Netflix adaptation in several ways. First, it facilitates the incorporation of David «Legal» Siegel, a character from a later book, which provides The Lincoln Lawyer Elliott Gould cameo. It also helps to remove a major book plotline connecting Mickey to his half-brother, Harry Bosch (whose appearances in Michael Connelley's books were adapted for the Amazon series Bosch and Bosch Legacy).
The character of Legal Siegel is a meaningful addition to The Lincoln Lawyer and change from the books. Siegel was Haller, Sr.'s law partner, and
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