Lane Arnold joined Diamond McCarthy in September 2008, following the completion of a one-year clerkship for the Honorable John H. McBryde, United States District Judge for the Northern District of Texas.

Lane received his J.D., cum laude, from the Southern Methodist University Dedman School of Law, where he was a recipient of the Hatton W. Sumners Foundation scholarship. While in law school, Lane served as a teaching assistant in the legal research and writing program, was a member of the International Law Review, and participated in the Criminal Justice Clinic. In the Clinic, Lane first-chaired two jury trials, obtaining "not guilty" verdicts in each for indigent clients charged with misdemeanor offenses. During law school, Lane also served as a summer extern for the Honorable Douglas S. Lang, Justice of the Court of Appeals for the Fifth District of Texas.

Lane earned his B.A., cum laude, in economics from Harvard College, where he was a member of the Harvard Crimson football team.