The turnaround in Baltimore was remarkably fast: It took a little under three weeks between Freddie Gray’s arrest and eventual death for a prosecutor to announce that the six officers involved had been charged.

This speed spoke to the incredible public scrutiny facing Baltimore, which had become the latest in an ever-growing list of cities rocked by protests over fatal encounters between police and black men.

It also pointed to a changed environment after nearly a year of unrest, one in which these episodes become national flash-points and authorities try to move quickly to provide answers.

“The climate and the expectations are different,” said David A. Harris, a law professor at the University of Pittsburgh and an expert in police use of force. “We want the standards to be the same. The law hasn’t changed.”

But if this had occurred more than a year ago, authorities could have waited for public attention to fade, Harris said. Now, amid a national debate over policing and protests that dominate the news, that is much harder to do.

“The question is, how seriously do you take the public’s desire for justice and some kind of answers?” Harris said. “And in the past, I don’t think they took that sort of desire quite as seriously as they do now.”

He said the past several months have changed the way these incidents are viewed by the public and by officials. Protests in Ferguson, Mo., New York and other cities across the country last year pushed such police shootings and other incidents into the public consciousness, turning each incident into part of something bigger, he said.

“What would have been in all probability a sort of local story and a local case a year ago now appears to fit this larger national narrative,” Harris said. As a result, this changes the public’s expectations regarding what answers they should be able to get from authorities, he said.

Since the protests in Ferguson last summer, authorities in the cities where demonstrations broke out have tried to respond quickly to stave off unrest. Legal observers, activists and other officials have said that one key lesson drawn from Ferguson is to respond quickly to protests to try and head off the kinds of protests seen in that city.

In Ferguson, after a white police officer shot and killed an unarmed 18-year-old, residents repeatedly criticized police for how slowly they released basic information. The grand jury process that ultimately cleared the officer was slower than usual because of how prosecutors showed evidence to jurors, pushing back the time when people would find out if any charges would be filed.

After video footage emerged showing a white South Carolina police officer shooting a fleeing black man in the back, police announced the same day that the officer had been arrested and charged with murder. That city’s mayor said his city had not turned into another Ferguson “because we did what is right.” As heavy protests broke out in Madison, Wis., over a fatal police shooting there, leaders quickly tried to reassure the public.

The mayor of Baltimore and governor of Maryland have been questioned for the speed with which they responded to the rioting that broke out  Monday after days of peaceful demonstrations in the city. Meanwhile, in a move that caught many by surprise due to its speed, less than a day elapsed between police handing their report to prosecutors and the announcement of the charges.

“What is surprising is the contrast between how this case moved and how similar cases might have moved in the past,” Harris said. “In the past there might not have been quite so much public focus and pressure to find out something, whatever it was.”

Six officers in Baltimore were charged with multiple counts Friday that include second-degree murder and involuntary manslaughter in the death of Gray, 25,  who died of injuries suffered while in police custody. 

“This historic moment is the result of the tireless efforts of families who have lost loved ones to police violence — here in Baltimore, throughout Maryland, and all across America,” Susan Goering, executive director of the American Civil Liberties Union of Maryland, said in a statement. “They persistently have called attention to the double standards of our criminal justice system.”

Police officers in the United States have historically rarely faced charges for using lethal force. A Washington Post investigation found that thousands of people were shot and killed by police over the past decade, while only 55 officers were charged in the shootings. Most recently, a Tulsa reserve deputy was charged with shooting a man after an undercover sheriff’s operation.

Researchers from Bowling Green State University studying violence-related police arrests between 2005 and 2011 found that nearly half of these arrests were for assault. A far smaller number were charged with murder or manslaughter.