JACKSON, Mississippy (AP) — A relative of Emmett Till is suing to try to make a Mississippi sheriff serve a 1955 arrest warrant on a white woman in the kidnapping that led to the Black teenager’s brutal lynching.

The torture and killing of Till in the Mississippi Delta became a catalyst for the civil rights movement after his mother insisted on an open-casket funeral in Chicago and Jet magazine published photos of his mutilated body.

Last June, a team doing research at the courthouse in Leflore County, Mississippi, found an unserved 1955 arrest warrant for Carolyn Bryant, listed on that document as “Mrs Roy Bryant.”

Till’s cousin Patricia Sterling of Jackson, Mississippi, filed a federal lawsuit Tuesday against the current Leflore County sheriff, Ricky Banks. The suit seeks to compel Banks to serve the warrant on Carolyn Bryant, who has since remarried and is named Carolyn Bryant Donham.

“We are using the available means at our disposal to try to achieve justice on behalf of the Till family,” Sterling’s attorney Trent Walker told The Associated Press on Friday.

The AP left a phone message for Banks on Friday, seeking comment. The sheriff did not immediately respond. Court records showed that the lawsuit had not been served on him by Friday.

Till, who was 14, had travelled south from Chicago to visit relatives in Mississippi in August 1955. Donham accused him of making improper advances on her at a grocery store in the small community of Money. A cousin of Till who was there has said Till whistled at the woman, an act that flew in the face of Mississippi’s racist social codes of the era.

Evidence indicates a woman, possibly Donham, identified Till to the men who later killed him. The arrest warrant against Donham was publicised in 1955, but the Leflore County sheriff at the time told reporters that he did not want to “bother” the woman since she was raising two young children.

Weeks after Till’s body was found in a river, her husband Roy Bryant and his half-brother JW Milam was tried for murder and acquitted by an all-white jury. Months later, the men confessed in a paid interview with Look magazine.

Now in her late 80s, Donham has lived in North Carolina and Kentucky in recent years. She has not commented publicly on calls for her prosecution.

The US Justice Department announced in December 2021 that it had ended its latest investigation into the lynching of Till, without bringing charges against anyone.

After researchers found the arrest warrant last June, the office of Mississippi Attorney General Lynn Fitch said in July there was no new evidence to try to pursue a criminal case against Donham. In August, a district attorney said a Leflore County grand jury had declined to indict Donham.

Walker, the attorney for Till’s cousin, said Friday that the South has a history of cases of violence that were not brought to justice until decades later — including the 1963 assassination of Mississippi NAACP leader Medgar Evers, for which white supremacist Byron de la Beckwith was convicted of murder in 1994.

“But for Carolyn Bryant falsely claiming to her husband that Emmett Till assaulted her, Emmett would not have been murdered,” Sterling’s lawsuit says. “It was Carolyn Bryant’s lie that sent Roy Bryant and JW Milam into a rage, which resulted in the mutilation of Emmett Till’s body into [an] unrecognisable condition.”