Michael Connelly wanted Matthew McConaughey for the role of Mickey based on his performance in Tropic Thunder (2008).
In "The Crossing" (2015), a Bosch novel by Michael Connelly that also features Haller, it's remarked that "He [Mick Haller] had received the ultimate imprimatur of L.A. acceptance - a movie about one of his cases starring no less than Matthew McConaughey." Furthermore, Haller was also asked by a reporter "if he had been in touch with Matthew McConaughey and if there would be a sequel to the Lincoln Lawyer film. Haller said he didn't know."
In the Mick Haller novel "The Fifth Witness" (2011) by Michael Connelly, a producer talks making a film about the case, and offers a suggestion who should play Haller: "I was thinking of going to Matthew McConaughey with this. He'd be excellent."