It’s a time of mourning in Dallas, Texas. Last week, concerns over police treatment of African-American residents and anger about the shootings of men like Alton Sterling and Philando Castile elsewhere in the United States led to a Black Lives Matter protest in downtown Dallas. Then, tragedy struck: Five police officers were massacred by a suspect who was later killed by officers after an hours-long standoff. As the city grieves police officers killed while protecting a peaceful protest, it’s worth remembering the life and death of Dallas’ first African-American police officer, William McDuff, whose story reveals the history both of black police officers in Dallas and the racial tensions that have plagued the city over the years.

McDuff was hired in 1896 after years of unsuccessful attempts to get African-American officers on Dallas’ police force failed, police historian W. Marvin Dulaney writes. He was appointed as a “special officer” to Stringtown, a predominantly poor, black neighborhood in the area now called Deep Ellum, in response to a series of disturbances near an AME church in the area. A newspaper report at the time noted that he was commissioned to keep order during services; it is unclear what his other duties may have been.

McDuff, who lived in what the reporter called a “humble cabin” in Stringtown, was an early example of police force diversity during an era when the first African-American police officers were being commissioned around the country. By all accounts, he was an upstanding and well-respected member of Dallas’ growing black community.

But not everyone was enthusiastic about his commission. On the night of December 25, 1896, just two months after he was commissioned, McDuff was accosted at home by two young African-American men whom he had reprimanded for laughing during a debate at the church. Witnesses reported that the young men used racial slurs to refer to the policeman before dragging him from his cabin and shooting him between the eyes. McDuff died instantly. He was soon surrounded by community members who were stunned by his murder.

Homer Stone and Jim Barclay were arrested for the murder and given 25 years and ten years, respectively, in the penitentiary. But though justice was served for McDuff, the way his death was reported at the time reveals the racial biases at play in Texas. “He was a special policeman, and was unpopular with a certain class of his own race," noted one report.

It would take half a century for another African-American to serve in the Dallas Police Department. The Dallas police refused to replace McDuff, ignoring pleas from the African-American community, even amid grisly, repeated attacks. For example, in 1921, a black elevator operator was whipped and paraded through the streets of Dallas after the initials “KKK” were burned into his forehead with acid—but the police department refused to investigate the crime.

Despite multiple recommendations from city commissions and mayors and even successful city council votes to instate African-American officers, members of the Dallas Police Department threatened to strike if any were commissioned. The Ku Klux Klan also organized local resistance to an integrated police force. It took until 1947 for Dallas’ next black police officers to be commissioned, but they were discriminated against and even prohibited from arresting white men. Today, the Dallas Police Department has an African-American police chief and the number of African-American officers slightly surpasses the city’s percentage of African-American residents.

McDuff is remembered as a trailblazer and one of the Dallas Police Department’s buildings is even named after him. But McDuff stands out for another reason—he is the only police officer killed on duty in Dallas for whom the department has no photograph. As the search for McDuff’s image continues, the memory of his service—and that of the struggles to represent African-Americans among the city’s police force—remains.