Sybrina Fulton and Tracy Martin, the parents of slain teenager Trayvon Martin, have spoken out about the tragedy in Charleston, South Carolina, saying they were “profoundly saddened” by the shooting at the Emanuel African Methodist Episcopal church that left nine people dead. They urged Americans to fight racism and to hold the shooter, 21-year-old Dylann Roof, accountable.

“[The country] must tackle the issue of racism head-on by holding individuals accountable for their murderous acts and not excuse their behavior by quickly labeling them as mentally ill in the media,” Fulton and Martin said in a statement, according to the Associated Press. They added that doing so “does a terrible injustice to those who are truly mentally ill."

Trayvon Martin died Feb. 26, 2012, in Sanford, Florida, after being shot by George Zimmerman. The incident launched a highly publicized trial that centered on Zimmerman’s alleged profiling of Martin, who was black. Zimmerman was ultimately acquitted of second-degree murder, a decision that sparked protests, rallies and vigils nationwide.

Roof claimed that the death of Trayvon Martin in 2012 “awakened” him to what he said were the “hundreds of these black on White murders [that] got ignored.” A racist manifesto of Roof’s beliefs surfaced online over the weekend.

“[T]his prompted me to type in the words ‘black on White crime’ into Google, and I have never been the same since that day,” Roof wrote of the Trayvon Martin shooting. “How could the news be blowing up the Trayvon Martin case while hundreds of these black on White murders got ignored?”