David Eyster assumed office as Mendocino County's elected District Attorney on January 3, 2011 for a four-year term.  DA Eyster was the senior supervisor and lead trial attorney in the same office from 1984 to 1996.

Mr. Eyster, then the challenger, out polled the incumbent in the November 2010 general election by over 7 1/2 percentage points, making that election outcome the widest margin of victory of any contested local District Attorney election in at least the last 40 years.

During the 2014 election cycle DA Eyster's bid for re-election was unopposed.  The last time an incumbent DA went unopposed in an election year in Mendocino County was in 1994, twenty years ago.

In 2016 DA Eyster was elected to serve a two-year term as a Director on the Board of Directors of the California District Attorneys Association (CDAA). He has also served as the co-chair of the CDAA Asset Forfeiture Committee.

During the 2018 election cycle DA Eyster's bid for re-election was again unopposed. This makes DA Eyster only the fourth DA since 1859 to be returned by the voters to serve a third term as Mendocino County's chief law enforcement officer.  DA Eyster was sworn into office to commence serving the current four year term on January 8, 2019.

During the 2022 election cycle DA Eyster's bid for re-election was again unopposed. This makes DA Eyster only the 2nd DA since 1859 -- and the first since 1950 - to serve a fourth term as Mendocino County's chief law enforcement officer. DA Eyster will be sworn into office to commence serving his fourth four-year in January 2023.

On September 29, 2022, the Governor signed into law AB 759, legislation that mandated a one-time term in office extension of two years for all California District Attorneys and Sheriffs elected in 2022. Thus, instead of having been elected to serve a four-year term in 2022, DA Eyster's 4th term in office will instead be a six-year term, beginning in January 2023 and running through December 2028.