CHICAGO (CBS) — Federal agents raided Illinois State Sen. Martin Sandoval’s office at the Illinois State Capitol in Springfield, and his home in the Gage Park neighborhood, on Tuesday.

As CBS 2’s Tim McNicholas reported, sources in the state Senate said the raids were a surprise to political insiders from Chicago to Springfield.

FBI Special Agent John Althen, a spokesman for the Chicago office, confirmed “FBI personnel are engaged in an authorized law enforcement activity at the Illinois State Capitol,” but declined further comment.

Agents could be seen walking out of the Senate Democrats’ offices carrying cardboard boxes and brown paper bags marked “evidence” before leaving the capitol.

Meanwhile, people in Gage Park said they were surprised to see a team of federal agents walking into the apartment building where Sandoval lives.

They stayed mostly silent as they left his home, carrying these cases and later boxes and a computer. One FBI agent told CBS 2 Sandoval was not inside the home.

The agents also would not say why they raided any of the locations as they packed up what they found and drove off.

People in Sandoval’s neighborhood say they know he lives there, but they don’t see him much. They say he mainly keeps to himself.

According to other published reports, FBI agents also were seen at Sandoval’s district office in west suburban Cicero. Witnesses said they also saw a team of federal agents at Sandoval’s home on the Southwest Side of Chicago.

An FBI vehicle is parked outside Sen. Martin Sandoval’s home on the southwest side of Chicago. A witness tells me saw a team of federal investigators here around 9 a.m. The FBI raided Sandoval’s Springfield office today. pic.twitter.com/xggO0Lt60K — Tim McNicholas (@TimMcNicholas) September 24, 2019

A Democrat from Chicago, Sandoval has been in the Illinois Senate since 2003.

Sandoval also chairs the Senate Transportation Committee, and was recently a chief negotiator for a $45 billion statewide infrastructure improvement plan signed into law in June.

The raid comes at a time when once-powerful Ald. Edward Burke (14th), whose ward shares some territory with Sandoval’s senate district, is facing a federal indictment for racketeering and bribery charges. Federal agents raided Burke’s ward office and City Hall office last November and again raided his City Hall office in December before announcing the first charges against him in January.

Burke, 75, pleaded not guilty to the indictment in June. He resigned earlier this year as Finance Committee chairman but was re-elected to a record 13th full term, despite the federal charges.

Former Ald. Danny Solis (25th) wore a wire for federal investigators as part of that probe. Solis resigned as Zoning Committee chairman in January after news of his cooperation with the federal probe broke. He did not run for re-election and has not been charged with a crime.

The feds listened in to more than 18,000 hours of Solis’ conversations in one year and on three occasions watched him come and go from massage parlors – visits allegedly paid for by a political fixer seeking favors.

Solis has not been charged with a crime, but the 120-page affidavit might explain why Solis chose to wear a wire to record conversations with former Finance Committee chairman Ed Burke.

Equally shocking are revelations in the affidavit that the FBI secretly recorded Illinois House Speaker Michael Madigan, whose House district makes up half of Sandoval’s district in the Illinois Senate.

The 2014 meeting at Madigan’s law firm, Madigan & Getzendanner, concerned a Chinese developer who wanted to build a hotel in Chinatown, in Solis’ 25th Ward, but needed a zoning change to do it.

An associate of the developer recorded the meeting on audio and video. According to the affidavit, Madigan made a pitch to secure the developer’s property tax appeals business saying, “We’re not interested in a quick killing here. Wwe’re interested in a long-term relationship.”

Solis later added, “If he works with the speaker, he will get anything he wants for that hotel.”

Madigan’s attorneys have said the speaker recalls several meetings with Solis over the past five years but is unconcerned, and to his knowledge is not under investigation.

That Chinese developer never hired Madigan’s law firm, and the hotel was never built.

It’s not clear if the raids on Sandoval’s offices are in any way connected to the Burke indictment or the Solis wiretaps.