A Michigan mother sued the city of Flint on Tuesday, alleging a school resource officer handcuffed her 7-year-old son for about an hour during an afterschool program in 2015.

The federal lawsuit alleges that the boy, who suffers from attention deficit hyperactivity disorder, was handcuffed after kicking a cart and running around bleachers during an afterschool program in October 2015.

The boy's mother, Chrystal McCadden, said that when she was arrived at the school, her 55-pound son was sitting on a foyer bench with his hands behind his back — and the officer didn't have a key to the handcuffs.

"When I walked in, he just jumped up and started crying," McCadden told reporters during a news conference shortly after the American Civil Liberties Union of Michigan announced the lawsuit.

McCadden said the officer told her the key to the handcuffs was being brought to the building by another officer.

"How do you handcuff someone and don't have a key?" she said Tuesday. "How do you handcuff a 7-year-old child?"

Her lawsuit seeks monetary damages and asks a judge to declare the officer's actions unlawful. Her son is now 10.

Along with the city, the lawsuit was filed against Flint's police chief, the school resource officer who handcuffed the boy and the Flint-area chamber of commerce that ran the afterschool program.

A spokeswoman for Flint said city officials haven't yet seen the lawsuit but that the city doesn't comment on pending litigation. The Associated Press also left a message Tuesday seeking comment from the chamber of commerce.

"The police should be dealing with crime and punishment," said Jonathan Marko, McCadden's attorney. "They should be policing our streets. They should not be policing our schools. They are not equipped to deal with children, especially children with disabilities."