"That's Wakiesha," Hines-Brim said as she walked away.
"That's Wakiesha!" she said again, her voice louder. "She's going to stay with you!"
Beck ordered an officer to arrest Hines-Brim, prompting other attendees to stand up and begin screaming.
The meeting abruptly ended, and the room was cleared.
Hazmat and fire crews were called to ensure that the substance wasn't hazardous, the Los Angeles Police Department said. Authorities later confirmed that it wasn't, though they have not determined what it was, Joshua Rubenstein, the police department's spokesman, said.
Hines-Brim and another woman, Melina Abdullah, were booked on suspicion of battery on a police officer. The agency said Abdullah, a Black Lives Matter activist and a professor at California State University at Los Angeles, assaulted an officer before the meeting room was cleared.
Abdullah said she and Hines-Brim were falsely arrested. The women were later released, Abdullah tweeted Tuesday night.
"I used her ashes so they can be with him, so he can feel her, because he murdered her," Hines-Brim said after her release from jail, according to KCBS. "They covered it up."
Asked by a reporter how she felt after her arrest, she said: "I feel satisfied."
Beck, who was seen by a medical personnel and did not require any treatment, said in a statement that the actions of the women were "disrespectful."
"This only created chaos and fear for any Angelenos who wanted to voice their opinion about policing in our city," he said.
Wilson was arrested March 26, 2016, after she was accused of assaulting a patient at a Los Angeles hospital, police said.
The following morning, she was found unconscious in her jail cell. A coroner's report said she had hanged herself.
Her death triggered protests from her family and Black Lives Matter activists, some of whom said Wilson wouldn't have killed herself and believed that an altercation involving officers was to blame, the Los Angeles Times reported.
Authorities said there was no evidence that officers used force against Wilson. After her death, the department reviewed practices on when to seek mental health assistance for an inmate and how family should be notified about deaths. Wilson's mother didn't find out that her daughter had died until after she had missed a court hearing, the Times reported.
In December, city officials agreed to pay nearly $300,000 to settle wrongful-death claims filed by Wilson's relatives.
The ruckus at the commission board meeting came two weeks after KNBC reported that a detention officer was fired following Wilson's death.
The NBC affiliate cited internal affairs and personnel files that showed the officer, Reaunna Bratton, was fired late last year over allegations that she had failed to immediately render medical aid to Wilson. Bratton also had been accused of violating jail policies by improperly isolating Wilson in an individual cell on the day she died.
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
OR IF YOU NEED TO TALK TO SOMEONE ELSE:
• LIFELINE: 0800 543 354 (available 24/7)
• SUICIDE CRISIS HELPLINE: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• YOUTHLINE: 0800 376 633
• NEED TO TALK? Free call or text 1737 (available 24/7)
• KIDSLINE: 0800 543 754 (available 24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• DEPRESSION HELPLINE: 0800 111 757