Newly released video from the commission meeting shows a woman being asked to leave after disrupting the commission meeting. As she walks out, she approaches the commissioners' dais and throws something down on the desk in front of Beck.
Ashes or powder float upward from the desk in the direction of Beck's face.
A hazmat team was called in to investigate the substance. Police described it as "ash-like" and said it was determined to be non-hazardous. The material was being further analyzed to determine if it was human remains, as some reports indicated, or a similar substance.
One of the women arrested was identified as Sheila Hines-Brim, who is an aunt of Wakiesha Wilson, a woman who died while in LAPD custody in 2016.
After she threw the substance down, she could be heard shouting: "That's Wakiesha! She's gonna stay with you!"
Hines-Brim was arrested for misdemeanor battery on a police officer.
Another woman was arrested after she allegedly assaulted an officer who was trying to clear the room. She was identified as Melina Abdullah, an activist with the Black Lives Matter movement in Los Angeles.
Lisa Hines said her sister became emotional because she believes Beck is protecting the officers responsible for Wakiesha Wilson's death.
"She just dropped a piece of paper to let him know that's how she feels about him. He's a piece of trash," Hines said.
"Because he's covering up the officers who killed my daughter, which is my sister's niece."
Wakiesha Wilson died while in LAPD custody in March 2016. Police said she was found hanging in her jail cell at the Metropolitan Detention Center, and the coroner's office ruled her death to be a suicide.
Activists disputed the ruling, arguing that Wilson was not suicidal. They also faulted the LAPD for failing to notify Wilson's family of her death.
The city agreed late last year to pay Wilson's family nearly $300,000 to settle a lawsuit they filed over her death.
City News Service contributed to this report.