Monday marks 10 years since a man armed with a rifle walked into the U.S. Holocaust Memorial Museum and opened fire.
Special Police Officer Stephen Tyrone Johns died in the shooting.
USHMM took out a half-page ad in the Washington Post Monday to honor Johns.
"While protecting visitors and colleagues, Special Police Officer Stephen Tyrone Johns was fatally shot on June 10, 2009 by an avowed antisemite, Holocaust denier and racist," the ad reads. "Officer Johns's outgoing personality and generous spirit endeared him to all who entered the museum, which was created to confront the very hate that took his life."
There is a plaque in honor of Johns in the lobby of the museum.
The man believed to be responsible for the shooting, James Von Brunn, died in federal prison in Butner, N.C. before going to trial.
Von Brunn was in his late 80s at the time of the shooting and his death. He was shot in the face by other officers returning fire during the museum shooting, but also had a poor history of health, according to previous reporting.
In 2010, one of the officers who returned fire said he felt cheated by the white supremacist's death in prison. Harry Weeks said he had hoped to testify against him and find him guilty.
"It was just sheer hatred that that man walked in and did what he did that day," Weeks said at the time.
The Washington Post previously reported Von Brunn had previously been convicted of going into a federal building while armed in 1981 and trying to place members of the Federal Reserve Board of Governors under citizens arrest for what he considered treason.