County Attorney's Office 2024

The County Attorney’s Office is comprised of a staff of over 49 dedicated public servants, including the County Attorney, Assistant County Attorney, Chief Deputy County Attorneys, Lead Deputy County Attorneys and Deputy County Attorneys, as well as administrative and support staff. Formerly, the functions of the County Attorney were performed by the District Attorney, an elected official, and the office was known as the Civil Division of the District Attorney's Office. On November 3, 1987, the voters of San Mateo County approved a Charter Amendment that separated the Civil Division from the District Attorney's Office and created the Office of the County Counsel. At that time, the Board of Supervisors appointed Thomas F. Casey III to serve as the first County Attorney. Thomas Casey served in the position for more than twenty years. Michael P. Murphy succeeded Mr. Casey in 2007 and served until 2011. John C. Beiers succeeded Mr. Murphy and served until 2022. Each of these individuals served with great distinction and exemplified the highest ideals of public service.

In March 2022 and the Board of Supervisors appointed John D. Nibbelin, as County Attorney.*  John D. Nibbelin joined the County Attorney’s Office in 2001 and was appointed Chief Deputy in 2011.The County Attorney’s Office, as the County's civil attorney, provides a full range of legal services to the Board of Supervisors, elected officials and all County departments, boards and commissions, special districts and school districts in San Mateo County. The County's mission is to provide excellent and cost-effective public service to improve the quality of life for all County residents. The County Attorney’s Office supports that mission and safeguards the legal integrity of the County on behalf of all residents of San Mateo County.

The goals of County Attorney are to:

  • Provide accurate, timely, useful and reliable legal advice protecting the County from loss and risk, and assisting our clients in making effective decisions among lawful alternatives.
  • Provide exemplary litigation advocacy; defend decisions and advocate the policies of our clients to achieve the best results – the lowest cost or loss-- without sacrifice of policy or principles.

 *In February 2022, the Board of Supervisors adopted an ordinance authorizing the use of the title of “County Attorney” in lieu of, or in addition to the “County Counsel” title. It is used for most purposes.