FERGUSON, Mo. — Police and protesters in Ferguson were finally able to share the streets again at night, putting aside for at least a few hours some of the hostility that had filled those hours with tear gas and smoke.

The St. Louis suburb still had plenty of lively protest Tuesday over the fatal police shooting of Michael Brown. And tensions rose briefly when someone hurled a bottle at officers.

But the overall scene was more subdued than the past five nights, with smaller crowds, fewer confrontations and no tear gas. Police said they still made 47 arrests, mainly of people who defied orders to disperse.

The slight easing of tensions came the day before Attorney General Eric Holder was to visit Ferguson to meet with FBI and other officials carrying out an independent federal investigation into Brown’s death.

In a letter published late Tuesday on the St. Louis Post-Dispatch website, Holder promised a thorough investigation while calling for an end to the violence in Ferguson. He said the bond of trust between law enforcement and the public is “all-important” but also “fragile.”

Arrest patterns “must not lead to disparate treatment under the law, even if such treatment is unintended. And police forces should reflect the diversity of the communities they serve,” Holder wrote.

He said the Justice Department would “defend the right of protesters to peacefully demonstrate and for the media to cover a story that must be told.”

The department has mounted an unusually swift and aggressive response to Brown’s death, from conducting an independent autopsy to sending dozens of FBI agents to Ferguson in search of witnesses to the shooting.

A grand jury also could begin hearing evidence Wednesday to determine whether the officer, Darren Wilson, should be charged in Brown’s death, said Ed Magee, spokesman for St. Louis County’s prosecuting attorney.

Wilson was recognized during a Ferguson City Council meeting in February, getting special recognition for what Police Chief Thomas Jackson said then was his role in responding to a report of a suspicious vehicle, then struggling with the driver and detaining him until help arrived.