Spencer's practice focuses on catastrophic personal injury and wrongful death cases involving defective medical devices, vehicular collisions, dangerous conditions of public and private property, and medical malpractice. Outside of his practice at Walkup, he also serves at the University of California-Berkeley Law School (Boalt Hall) as a lecturer in trial advocacy. In addition to his teaching, he directs Berkeley Law's external trial competition program, and coaches three trial advocacy teams. Under Spencer's guidance, the program has risen to national prominence, having won many national honors and distinctions, including a national championship. Spencer has also provided ongoing legal education, including developing and co-chairing programs produced in conjunction with Berkeley Law, with a special focus on providing training to young attorneys. He has also co-chaired a presentation on governmental liability and design immunity, spoke to leading trial associations regarding governmental liability, and offered presentations on liability for commercial carriers.