The Justice Department has begun work on a legal memo recommending no civil rights charges against a white police officer in Ferguson, Mo., who killed Michael Brown in August, law enforcement officials said.

That would close the politically charged case in the Brown shooting. The investigation by the FBI., which is complete, found no evidence to support civil rights charges against the officer, Darren Wilson, officials told the New York Times .

A broader civil rights investigation into allegations of discriminatory traffic stops and excessive force by the Ferguson Police Department remains open, however. That investigation could lead to significant changes at the department, which is overwhelmingly white despite serving a city that is mostly black.

The state authorities concluded their investigation into Brown’s death in November and similarly recommended no charges.

There is a high legal bar for bringing federal civil rights charges, and federal investigators had for months signaled that they were unlikely to do so. The Justice Department plans to release a report explaining its decision, though it is not clear when.