About Our Office

David Joseph Sutton, Public Defender

David Joseph Sutton, Public Defender - David Joseph Sutton has dedicated his legal career to indigent defense and social justice.  David's legal career began with an internship at the Marin County Public Defender’s Office in the summer of 2006. Following graduation, David worked as a Deputy Public Defender in Marin County. David was appointed to serve as the Marin County Public Defender in September 2021.

Before returning to Marin County, David was a Federal Public Defender for 10 years. David most recently served as the Los Angeles Trial Chief at the Federal Public Defender’s Office for the Central District of California. David has represented clients in various criminal matters, including misdemeanors, serious felonies with decades-long mandatory minimum prison sentences, white-collar and medical frauds, and cases punishable by the federal death penalty.

David received his Bachelor of Arts from San Francisco State University and a Juris Doctorate from the University of San Francisco School of Law.  David currently sits on his law school’s Board of Governors. He is also a current member of the State Bar of California’s Judicial Nominations and Evaluations Committee.

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Christine O'Hanlon, Chief Deputy Public Defender - Christine O’Hanlon is lifetime California resident growing up in Vallejo, California. She earned her bachelor’s degree in psychology from University of California, Santa Cruz. Ms. O’Hanlon attended and graduated with a J.D. from California Western School of Law in San Diego.

Since being admitted to the Bar in 1996, Ms. O’Hanlon has specialized in the defense of indigent individuals. She started her career in juvenile court in San Diego. In 1997, she returned to Northern California and worked in the Juvenile Division in the Solano County Public Defender’s Office. In January of 1999, Ms. O’Hanlon joined the Marin County Public Defender’s Office where she has remained.

Ms. O’Hanlon has extensive litigation experience in juvenile, misdemeanor, and felony cases taking a multitude of cases to trial. In addition to litigation, Ms. O’Hanlon places a premium on holistic representation and actively pursued starting Marin’s Mental Health Court, “STAR Court” to ensure Marin’s most vulnerable clients receive the services they need to live productive and law abiding lives. She brings this holistic approach to all Public Defender clients with the commitment clients better their lives making the community better for everyone.

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Peter L. Arian, Chief Deputy Public Defender - Peter L. Arian (J.D. UC Law SF 2005) began his legal career at the Marin County Public Defender as a 2L law student in 2004).  For the last 20 years, Peter has helped people who find themselves in the criminal justice system.  Peter served as a deputy public defender in Marin from 2005-2012, an assistant federal public defender for the Central District of California from 2012-2015, and a solo criminal defense practitioner from 2015-2023.  During that time, Peter tried cases to verdict ranging from DUI to special circumstance murder.  Peter’s capital case experience includes appointments as lead counsel in death penalty cases in state court, post-conviction representation of death row inmates, and appointments as either lead or learned counsel in federal death penalty cases in the Northern, Eastern, and Central Districts of California.  From 2013-2015, Peter represented detainees in Guantanamo Bay.  Peter’s accomplishments in both state and federal court include dismissals of murder charges in multiple cases, and well as successfully obtaining decisions by the government to seek punishment other than death.  Peter has served on the Los Angeles Bar Association Judicial Appointments Committee (2013-2015), and the CJA Panel for the Northern District of California.  From 2019-2022, Peter taught as an adjunct professor at USF School of Law. He has guest lectured at UC Law SF, UCLA School of Law, and Loyola School of Law, and for the past six seasons coached the San Rafael Mock Trial Team.  Peter speaks Spanish fluently.  Peter’s father Stephen (J.D. UC Law SF 1966) preceded him both in the practice of law and at the office, giving clients of the Marin County Public Defender thousands of hours of free legal services as a volunteer attorney from 2001-2006, during which time he was twice voted the County’s Volunteer of the Year.

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Rose Spikes, Administrative Services Officer - Rose Spikes undertook an internship with the Marin County Public Defender’s Office in 1999 while pursuing her education at Santa Rosa Junior College. Following her graduation, Ms. Spikes transitioned into a permanent role as a Legal Secretary within the department. Subsequently, she earned a promotion to her current position as the Administrative Services Officer, where she oversees Budget, Finance, HR, and grant management. Ms. Spikes has maintained a longstanding commitment to the County, driven by her deep passion for supporting the mission of the Public Defender’s Office. For her, employment extends beyond administrative duties; it is about actively contributing and participating in the overarching objective of ensuring justice for all individuals, irrespective of their circumstances.

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Jonathan Dagg, Chief Investigator - Jonathan Dagg has been with the Public Defender’s Office since 1999.  He supervises the Investigation Division as well as conducts felony and misdemeanor defense investigations. Jonathan holds a bachelor’s degree from California State University, Sacramento and is a Certified Criminal Defense Investigator.  He is also a licensed Private Investigator and an active member of the California Defense Investigators Association. 

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