“We’re not out of the woods yet,” Gov. Larry Hogan said, even as crowds gathered in the streets not only in Baltimore but also in other major cities, including Ferguson, Mo., Minneapolis, Washington and Boston. In New York, several hundred people gathered in Union Square Park, and at least 60 were arrested after they poured into nearby streets.

Just before the second night of Baltimore’s 10 p.m. curfew, a fistfight broke out at the west side intersection where much of the looting and violence occurred earlier this week. But the crowd dispersed quickly once the curfew was in effect. More than an hour into the curfew, the city appeared relatively quiet, and the police seemed to have a less forceful posture on the street.

Image A protester outside City Hall on Wednesday. Rallies were held in several other major cities, including Boston and New York. Credit... David Goldman/Associated Press

Earlier Wednesday, the state’s attorney’s office, like the Baltimore civic leaders, also tried to lower expectations for Friday. Receiving the police report is just part of the investigation process by the state’s attorney, said Rochelle Ritchie, the communications director for Ms. Mosby. “When the state’s attorney comes out and gives something, it’s going to be something substantial,” Ms. Ritchie said. “You’re not going to see little bits and pieces here and there. When it is time to come forward, we will do that. I can’t say when it’s going to be.”

The state chief medical examiner’s office has also warned that preparing an autopsy report usually takes 60 to 90 days. Even after the investigations finish, the prosecutor’s office, if it decides to seek charges, must present the case to a grand jury and ask for an indictment. If there are to be criminal charges, they probably remain months away.

Officials said another potential flash point is a demonstration planned for Saturday, organized by Malik Z. Shabazz, an activist who has likened the police to an occupation force.