They wanted to teach the city a lesson.
They requested thousands of hours of police radio communications and questioned top police officials under oath for days about department policies. Through their attention to detail, they reconstructed nearly every minute of the Sept. 27, 2002, march against the World Bank from the moment it started to the minute the orders were given for the mass arrests in Pershing Park.
The tedious approach to assembling facts is a staple of their three-person law practice, the Partnership for Civil Justice, and reflects a deeper personal passion to defend the Constitution and create social change.
"It's not enough for us to say, 'We are asking [D.C. police] to stop beating people,' or whatever the violation is," Messineo said. "We take it a step further and try to identify what it is exactly that is causing the violation to occur, because we want to make sure it never happens again to someone else."
In the process, the partnership has won some high-profile cases and made the city pay.
They won a battle to have a Trinidad neighborhood police checkpoint program struck down as illegal and forced D.C. police to release thousands of documents detailing internal policies on high-speed chases, recording interrogations and other use of police powers. And they've obtained more than $14 million in damages on behalf of protesters who were unjustly arrested by D.C. police over the years.
Nationally, they got more space for protesters along the inauguration parade route and in New York's Central Park, where demonstrators were banned in advance of the 2004 Republican convention.
All the while, they've managed to stay married.