Chicago (CBS) — Cook County Board President and Chicago mayoral candidate Toni Preckwinkle fired a key political adviser because of remarks he posted on social media.

Preckwinkle released a statement Thursday night stating that Scott Cisek was no longer affiliated with her campaign.

“His recent social media post was unconscionable and showed insensitivity to the issue of anti-semitism. It does not reflect my values or the values of my campaign. I apologize to Lori Lightfoot and everyone who was offended by this insensitive comment,” the statement says.

According to the Chicago Sun-Times, Cisek posted a photo of the Nuremberg Trials to Facebook with a caption that said “Just following orders.”

The post was in response to mayor candidate Lori Lightfoot saying she had been following advice from more experienced prosecutors in an incident that resulted in her being reprimanded by a federal judge.

Cisek took the post down, and Preckwinkle released her statement about her adviser’s dismissal shortly before midnight Thursday.

Lightfoot released a statement about the incident.

“Politics is a tough business,” she said. “I knew that before I jumped in. But it is disturbing to me that a mayoral candidate’s top adviser believes the genocide of millions of people is a casual enough subject to be used as a joke to settle a political argument. Take note of those that surround the people we expect to lead.”

Cisek’s Twitter account is no longer active as of Friday morning.

Cisek also had been a top assistant to Preckwinkle in Cook County government, but resigned that county post in October. A spokeswoman said there are no plans for the county to rehire Cisek.