In a press conference following the Freddie Gray riots that rocked Baltimore, Mayor Stephanie Rawlings-Blake famously explained to reporters that “we provided spaces for protesters to destroy if they chose to do that.”

In a follow-up interview, Rawlings-Blake clarified that she and the police tried not to escalate the riots, with Baltimore Police Commissioner Anthony Batts writing in an email, “In short, because this was a protest against the Baltimore Police Department, we couldn’t be seen as the aggressors or instigators, as such we needed to give them space. Going forward we will tighten up the reins on the marches to ensure everyone’s safety.”

Batts was fired, and the permanent hiring of his replacement, Kevin Davis, was met with protests and an overnight occupation of City Hall by demonstrators who insisted on a meeting with him to present a list of 19 demands, including “larger and more disruptive spaces than would normally be tolerated” for protests.

That’s how the stage has been set for tonight’s protests following the proclamation of a mistrial in the case of William Porter, the first of six police officers to be tried in connection with the death of Freddie Gray. Activist groups like Baltimore BLOC had prepared in advance for a not guilty verdict, but news of a mistrial was good enough reason to take over the streets.