Ten activists who authorities say helped orchestrate a large-scale protest at the Mall of America against police brutality in December have been formally charged, Bloomington police said Wednesday.

The group was charged with crimes ranging from unlawful assembly and public nuisance to trespassing and disorderly conduct, according to a complaint filed in Hennepin County District Court.

The charges mark the most forceful action against a protest movement that has sprouted in Minneapolis and in other major U.S. cities in recent months in response to the recent police killings of unarmed black men.

Local activists reacted with widespread criticism of Bloomington authorities.

"These charges are absurd," said Mica Grimm, one of the organizers facing charges. "We will not let these charges silence us."

Those facing charges say Bloomington officials are unfairly threatening to recoup costs for policing a peaceful demonstration. "The implications of forcing protesters to pay for police presence they didn't ask for sets a dangerous precedent," Grimm said.

Those charged include: Grimm, 24; Nekima Levy-Pounds, 38; Michael Anthony McDowell, 21; Jie Rose Wronski-Riley, 18; Todd Allan Dahlstrom, 49; Kandace Leanne Montgomery, 24; Catherine Claire Salonek, 26; Adja Sara Gildersleve, 26; Shannon Lee Bade, 45, and Amity Lebaube Foster, 38.

After the arrest of 25 people on trespassing charges at the mall on Dec. 20, Bloomington City Attorney Sandra Johnson said authorities would work to identify and prosecute those who had engineered the unsanctioned demonstration. The event drew thousands to the mall, and several businesses opted to close for several hours on one of the busiest shopping days of the year.

Local leaders of the American Civil Liberties Union (ACLU) said they are considering intervening legally, and nearly 250 people had already donated to an online legal defense drive for those charged.

"It feels personal. It feels like a vendetta," said Teresa Nelson, legal director for the ACLU's local chapter.

Nelson said Johnson's comments "referring to it as a powder keg waiting for a spark," were inflammatory and overblown.

Other activists urged more restraint from Bloomington officials.

"There are other alternatives. Just use discretion in that office: When you have all the power, you have all the options," Jeff Martin, president of the St. Paul chapter of the NAACP, said at a news conference Wednesday. "We ask her to consider all those options."

Social media aids IDs

Authorities identified the protest's organizers through social media postings before and after the rally and also honed in on those who gave media interviews. Plainclothes detectives also infiltrated one of the group's planning meetings before the mall protest.

"The mall's got an amazing video surveillance system, and it's pretty easy with high definition to identify people," Rick Hart, Bloomington deputy police chief, said Wednesday. "Plus, those people were very active on social media and with the media."

Hart said some of the protesters may be on the hook for the city's $25,000 overtime bill to beef up security on the day of the protest. If convicted, the protesters could be ordered to pay restitution, he said.

The Mall of America rally represented the most high-profile local protest to date of the recent grand jury decisions not to indict white police officers in the deaths of unarmed black men in New York and Missouri.

After several hours, riot-gear-clad police officers moved in to peacefully disperse the remaining protesters, some of whom had staged "die-ins" in front of several nearby businesses. Several stores in the eastern section of the mall were shut down for a brief period.

Libor Jany • 612-673-4064 Twitter:@StribJany