Justin Marceau

Professor Justin Marceau is a Professor of Law, the Brooks Institute Faculty Research Scholar of Animal Law and Policy, and the Faculty Director of the Animal Law Program. Marceau also co-founded and helps direct a first of its kind law school clinic, the Animal Activist Legal Defense Project, which provides activists with representation in criminal and civil litigation.

Marceau’s research is broadly focused on criminal law, civil rights, and animal law. He has done extensive research on habeas corpus and capital punishment, including empirical scholarship that has contributed to ending the death penalty in more than one state. Marceau is the author of more than 40 academic articles and essays, and two textbooks. His first book, Beyond Cages, was published by Cambridge University Press in 2019 and serves as one of the first extended critiques of carceral animal law. His second book was an edited volume with Lori Gruen titled Carceral Logics, which examines notable connections between animal protection and human protection efforts. His most recent book, Truth and Transparency, was co-authored with Alan Chen, and was awarded the Tankard Prize, which is awarded to the “most outstanding book in the field of journalism and communication.”

Marceau serves as the reporter for the pattern criminal jury instruction committee of the U.S. Court of Appeals for the Tenth Circuit. He was an inaugural member of the Governor’s Council for Animal Protection, and he serves as a member of an oversight committee for the Colorado Bureau of Animal Protection. He is on the advisory board for the Cambridge Centre for Animal Rights, and is a Fellow of the Oxford Centre for Animal Ethics.

Marceau is the recipient of numerous awards, including the Justice for Animals Award and the Colorado Criminal Defense Bar’s Gideon Award. He is a member of the American Law Institute, and he was a visiting professor at Harvard Law School in 2020 and UC Irvine in 2021. In 2023, Vox selected him as one of the “Future Perfect 50,” which honors fifty people across the world who are recognized for their distinct efforts to make the future better.

Prior to coming to DU, Marceau was an assistant federal public defender specializing in capital habeas and a law clerk for the Ninth Circuit Court of Appeals. Before law school, he spent a year living and working in Cairo, Egypt.  

Marceau has lectured on his research in the U.S., Canada, and in Europe, has been retained as an expert witness in criminal and civil cases, and received grants and awards for his research from a variety of organizations. He is a member of the Colorado and California bars, and has maintained a law practice while teaching at DU.  Marceau has recently represented indigent persons, persons sentenced to death, and a wide range of public interest non-profits. He also frequently authors or contributes to amicus briefs, most often on issues relating to animal law or habeas corpus.

Marceau received a JD from Harvard Law School and a BA from Boston College.  

View CV

• JD, cum laude, Harvard Law
• BA, summa cum laude, 2000, Boston College (Philosophy)

• California Bar
• Colorado Bar