Ken Carlson, left, and Debora Allen were the top vote-getters in the June primary and are facing each other in November to succeed Karen Mitchoff in District 4 on the Contra Costa County Board of Supervisors. (Photos courtesy of the candidates)

Filling the seat of Contra Costa County Board of Supervisors chairperson Karen Mitchoff won’t be as simple as just winning a local election.

It was already tried once in June, with none of the five candidates getting more than 50 percent of the vote.

The two top vote getters — Pleasant Hill City Council member Ken Carlson (26.73 percent) and BART board member Debora Allen (25.26 percent) — will square off Nov. 8.

District 4 includes parts of Walnut Creek, Pleasant Hill, Concord and Clayton.

The county Board of Supervisors runs in Carlson’s family. His grandfather, James Moriarty, was a Contra Costa County supervisor.

Carlson was a Concord police officer for 29 years, doing everything from patrolling to working on the county’s forensic mental health team.

Carlson has served as Pleasant Hill’s mayor and was the City Council’s first openly gay member. He says he will focus on public safety, the housing crisis, economic recovery and fighting climate change.

Allen was elected to the BART board in 2016. Her campaign site says she is a “common-sense, no-nonsense candidate with a reputation for challenging the status quo” and a “fiscal hawk.”

She has more than 30 years of experience in construction and real estate management, which she says will help her when it comes to job creation and tackling the housing crisis.

Contra Costa voters can find more information about the process on the county’s website. The California Secretary of State’s office has details on how to register to vote in California.

Those registering or re-registering fewer than 15 days before an election need to complete the same day voter registration process and request a ballot in person at their county elections office or polling location.

People can contact the Contra Costa County Elections Office at 925-335-7800 or by email, and can check if they are already registered to vote.