WAUWATOSA, Wis. — Fifty people are suing a Wisconsin city over the way it handled protests last fall after authorities announced that a police officer would face no charges for the fatal shooting of a Black teenager.

Protesters demonstrated in Wauwatosa in October after the Milwaukee County District Attorney had announced that Wauwatosa Police Officer Joseph Mensah would face no criminal charges in the February 2020 shooting death of 17-year-old Alvin Cole outside a mall. City officials had enacted a 7 p.m. curfew and called in the National Guard amid fears that protests could turn violent.

The lawsuit, which was filed Saturday, claims that the emergency order for the curfew was unlawful and violated the constitutional rights of protesters. It names the city, the police chief, and Mayor Dennis McBride as defendants.

Cole’s mother, Tracy Cole, is among the 50 plaintiffs who claim they were ticketed, arrested or harassed in Wauwatosa for protesting.

“There is no factual or legal merit to the allegations in the complaint, and we expect to fully prevail,” McBride told Wisconsin Public Radio.

The lawsuit also claims that the police department and “other operational partners” responded to the demonstrations with “brutal, violent and unconstitutional tactics.”

The protests led to the arrest of dozens of people, including members of Cole’s family.

Cole was shot five times by Mensah after he fled from police following a disturbance inside the Mayfair Mall.

Mensah, who also is Black, said he shot Cole because he had pointed a gun at him. It was the third time since 2015 that Mensah had fatally shot someone while on duty. He was not charged in any of the deaths. He has since resigned from the police department.