Despite plummeting temperatures last week, about two dozen people filled a classroom on the seventh floor of the School of the Art Institute one evening for a workshop on the basics of “cop watching.” While the idea of observing police has become tightly linked in recent years with bystanders filming officers, the organizers of the training emphasized that cell-phone cameras aren’t required to keep an eye on cops.

Last week’s workshop focused on how to conduct oneself if one chooses to observe a police stop, and what to do if the cop being watched turns his or her attention to the watcher.

Conversely, one’s right to remain silent during questioning must also be affirmed. If you happen to be arrested and invoke the right to remain silent, any further conversations with officers—even a request for water or permission to go to the bathroom—is legally seen as a withdrawal of the invocation and anything you say further can be used by the police and prosecutors to build a case against you. Even after a brief and seemingly irrelevant exchange of words, one must restate one’s desire to remain silent or not talk without a lawyer.

PRT advises that a person observing a police encounter should stand “within grabbing distance plus one step” away from officers. They may tell you to move away further, and it’s best to comply, even if you think an officer isn’t issuing a “lawful” order. “The bottom line is the law matters in court, it doesn’t matter so much on the street,” Mills says. “Playing lawyer on the street is the quickest way to get arrested or, in the worst circumstances, to get shot.”

“We just need more people [leading cop-watching workshops],” Trinidad said. “There’s this whole idea that we are gonna be safe when cops have the video cameras, but we know they just turn them off. We know that’s not fixing anything. What we need is more people to be aware of their surroundings and be cop watching themselves and feeling more comfortable in intervening.”