The attorney is a Chicago alderman. The aldermans south side and city hall offices were raided. The FBI did go near the law firm. The law firm performed property tax work related to Trump Tower.
In Chicago, two law firms handle most of the property tax work for the downtown area: this aldermans firm and Mike Madigans firm. Property taxes in Chicago are extremely high, especially for high rises in the city.
The property tax work is one source of corruption but it is not what the FBI was after yesterday.
Im correcting my previous post. The FBI did not go near the law firm.