Honorable Mary Ann O’Malley — Department 4

Biographical Information

  • Education: She graduated from Mills College and Golden Gate School of Law
  • Pre-bench Legal Experience: While in law school she clerked for the Contra Costa District Attorney’s Office, and became a Deputy D.A. after passing the bar. While at the D.A.’s office she handled a variety of cases, including homicide and sexual assault.
  • Political Affiliation: No party affiliation


Judicial Experience

Judge O’Malley was appointed by Governor Pete Wilson in 1996. Appointed in 1998 to Contra Costa County Superior Court, she has served in the Richmond, Mt. Diablo, Delta, and Martinez courts. Served as the Supervising Criminal Judge from 2005 – 2009, and Presiding Judge Contra Costa County 2009-2011.


Pre-bench Civic & Professional Activities

Served on the Dispute Resolution Board and the Child Death Review Team. From 1988 to 1998, Judge O’Malley taught extensively at Los Medanos Police Academy, the Reserve Academy and Dispatch Academy where she taught in the areas of Crimes of Property, Crimes of Persons, search and Seizure and Courtroom Demeanor. She also taught Advanced Officer Training in the areas of Homicide and Search and Seizure. 1996-1998, Professor at Contra Costa College teaching criminal procedure. 2000 to present, Instructor for CJER – NJO Trials and Evidence and Seminar Leader and instruction to Judges on how to teach Trials and Evidence at NJO. 2003-present, Instructor at the B.E. Witkin Judicial College – Search and Seizure and Seminar Leader. 2007 to present, Instructor for CJER – Winter Continuing Judicial studies Program, Search and Seizure, and Homicide.


Civic & Professional Activities

2000-2009, Chair of Court Training and Education Committee. 2004-2007, served on the Judicial Advisory Committee. 2004 to present, Chair of the Court Operations Committee. 2005 to 2009, Supervising Criminal Judge. 2005 to present, Member of CCC Superior Court Executive Committee. 2007 to 2009 Assistant Presiding Judge Contra Costa County. 2008-2010, CJER Criminal Law Education Committee. 2009 to 2011 Presiding Judge Contra Costa County. 2009 to present, Trial Court Presiding Judge Executive Committee. 2009, Trial Court Presiding Judges Joint Legislation Advisory Committee. 2009-2010, Chair of the Trial Court Presiding Judges Advisory Committee on State Budget. 2009 to present, Chair of the Trial Court Presiding Judges Advisory Committee. 2009-2010, Advisory Member of the Judicial Council of California. 2009-2011, Member of the Trial Court Budge Working Group. 2009 to present, PJ CEO Rules and Roles Analysis Working Group. 2009-2010, Member of the Executive and Planning Committee of the Judicial Council. 2010 to present, Judicial Recruitment and Retention Working Group. 2010, TCPJAC/CEAC Joint Working Group on Rules. 2010, Chair of Limited Court Closure Working Group. 2010 to 2012, Member of the CJER Criminal Law Curriculum Committee. 2010 to 2014, Voting Member of the Judicial Council of California. 2010-2011, Member of the Advisory Committee on Financial Accountability and Efficiency for the Judicial Branch. 2011, Chair of the Court-Ordered Debts Task Force. 2010-2011, Member of Rules and Projects Committee of the Judicial Council. 2011-2012, Member of the policy Coordination and Liaison Committee of the Judicial Council. 2011-2012, Chair of the Dependency Council Reimbursement Working Group. 2013-2014, Executive and Planning Committee of the Judicial Council. 2013-2014, Chair of the Litigation and Management Committee of the Judicial Council. 2013-2014, Internal Chair of the Judicial Council.


Community Involvement

2001 to present, Reader at Burton Elementary School for Read Across America Day. 2006 to present, Panelist Judge for Teacher of the Year Awards for Contra Costa County.


Continuing Legal Education Faculty

Instructor on Homicide for CJER winter continuing Judicial Studies Program; Instructor for CJER at the judicial college and Seminar Leader.


Recent Publications

1988 Tactics, CDAA 3rd Edition, Opening Statements, Co-author.


Courtroom Policies

Attorneys should exchange jury instructions, witness lists. Be prepared to argue motions in limine. Documents should be presented at the outset if any issues are anticipated. Be prepared to try your case.



See In Limine below.



Stay Away from boilerplate language.


In Limine Motions

Written motions in limine not necessary, but be prepared to argue them.


Voir Dire

Time for voir dire varies case by case.


Jury Instructions

Attorneys should submit to the Court at the outset of trial. People submit to defense counsel at outset of trial. Defense submits to People at conclusion of People’s case.



Attorneys should submit a list to the Court at outset of trial. Be ready to call consecutive witnesses, on day two of trial, with no down time.






Each morning of trial, counsel should come early, show to opposing counsel all documents for that day and have the court mark the documents. All evidentiary issues should be resolved before the start of trial.



General professional decorum.


Court Reporters & Translators

If an interpreter is needed, resolve early with the court clerk or attorneys should take care of it themselves.


Computers in the Courtroom

While the courtroom isn’t equipped for Powerpoint, Judge O’Malley will help in providing whatever assistance is necessary to facilitate such a presentation.



Same as above.


Cameras in the Courtroom

Evaluated on case by case basis.



Counsel who appear before me, don’t need advice.