His research, teaching, and public engagement focus on criminal punishment, though he’s also interested in politics, labor unions, sports, and an assortment of other topics. He’s the author of The Toughest Beat: Politics, Punishment, and the Prison Officers Union in California (OUP, 2011), and he’s currently writing a book with Michelle Phelps and Phil Goodman titled Breaking the Pendulum: The Long Struggle Over Criminal Justice.