CONCORD — The FBI raided the home of the influential and often-victorious political consultant Mary Jo Rossi, drawing immediate speculation as to which — if any — of her many friends in politics might also be involved in the criminal probe.

The FBI raid on Rossi’s home on Thornwood Drive in Concord came Thursday. An FBI spokeswoman would confirm only that the agency served a search warrant there, not what they seized or why, stating that it was part of an “ongoing investigation.” No other related raids were conducted Thursday, FBI spokeswoman Cameron Polan said.

“I can’t say anything else at this time,” Polan said.

Rossi could not be reached for comment.

Rossi is prolific in Bay Area politics, having served in high-ranking staff or consulting roles for Contra Costa Supervisor Candace Andersen, former Contra Costa Supervisor Federal Glover, Contra Costa Sheriff David Livingston and state Assemblymember Willie Brown, who later became mayor of San Francisco.

She has a reputation of making winners out of candidates, even if it means drawing controversy for using aggressive tactics in the process.

In recent years, she has consulted for police officer unions, homebuilders and a major garbage-handling company, Mt. Diablo Resource Recovery, which is operated by the influential Garaventa family of Contra Costa.

In January, Rossi appeared to have distanced herself from the Garaventas’ business, alleging in emails to reporters and state Assemblymember Ana Marie Avila Farias, D-Concord, that misconduct by the company’s officials had gone ignored.

With a penchant for representing controversial figures — another of her recent clients, the Seeno family of land developers, has fought numerous environmental lawsuits — Rossi has earned a reputation as among the most well-connected political insiders in the Contra Costa County’s mostly suburban central region.