The Justice Department has decided not to bring charges against the officers involved in the death of Alton Sterling, whose videotaped shooting by police in Baton Rouge last summer prompted unrest across the city, and is planning to reveal in the next 24 hours that it has closed the probe, sources tell the Washington Post.

As of Tuesday afternoon, it is unclear how and when the department will announce its findings.

The case will be the first time under Attorney General Jeff Sessions that the department has publicly declined to prosecute officers investigated for possible wrongdoing in a high-profile case.

Baton Rouge officials are girding for possible reaction there. Sterling’s death last summer sparked tense protests across the city.

Substantiating federal civil rights charges is extraordinarily difficult, requiring prosecutors to present evidence that might speak to an officer’s intent at the time of the incident.