In a multi-day mission over the summer, the city of Boston, including its police and public works departments, organized and executed what it described as “Operation Clean Sweep.”

The operation resulted in dozens of arrests in the area around Melnea Cass Boulevard and Massachusetts Avenue, where there are a number of substance abuse recovery programs and shelters.

Mayor Marty Walsh argued everyone arrested had warrants and not a single person was arrested just for being homeless or addicted to drugs.

Matt Segal, legal director at the ACLU of Massachusetts, told Boston Public Radio Tuesday the city's actions amounted to collective punishment, and the organization wants more information about potential civil rights violations.

"If somebody in one of our neighborhoods commits a crime, we would not expect the police to come swooping in and ransack our communities," said Segal. "The law doesn't apply differently when the people involved are people experiencing homelessness."

The ACLU filed a lawsuit against the city at the end of of September, citing an inadequate response to a request for information about the events that transpired.

"We sent a letter to mayor of Boston saying, 'It looks like there are serious problems here, we're hearing reports about collective punishment, we're hearing reports about people having their items confiscated and possibly crushed in garbage trucks,'" Segal said. "This raises serious concerns about people's rights."

That letter included a public records request, and the ACLU said it found the city's response unsatisfactory.

So they filed a public records lawsuit "to get to the bottom of what really happened, and also to help us understand whether there have been serious violations of people's rights."