March 30 (UPI) -- FBI agents raided a home just outside Detroit in connection with reported death threats made against the judge and attorneys involved in a trial for the men who plotted to kidnap Michigan Gov. Gretchen Whitmer, authorities said Wednesday.
The subject of the raid was a home in a northern suburban neighborhood, according to FBI Special Agent Mara Schneider, who serves as a spokesperson for the agency's Detroit field office.
"FBI Detroit will work closely with other FBI field offices and with our law enforcement partners across the country to identify the source of any threat made to anyone involved with the ongoing prosecution in Grand Rapids," Schneider said in a statement reported by NBC News.
"Individuals found responsible for making threats in violation of state and/or federal law will be referred for prosecution in the appropriate jurisdiction."
On Tuesday, the Detroit News reported that threats had been made against Chief U.S. District Judge Robert Jonker and defense attorneys Josh Blanchard and Christopher Gibbons, according to two unnamed sources familiar with the incidents.
The FBI also is investigating claims that former FBI informant and key witness in the case, Steve Robeson, received a death threat via a Wisconsin newspaper, Schneider told the Detroit Free Press.
Prosecutors are attempting to paint Robeson as a "double agent," claiming that he was helping the four Michigan militia members develop and carry out their plan to kidnap Whitmer even as he was supposed to be investigating them.
If ordered to testify, Robeson said he plans to plead the Fifth Amendment against self-incrimination.
The alleged threats are under investigation as the trial for Barry Croft Jr., Adam Fox, Brandon Caserta and Daniel Harris stretches into its third week.
Prosecutors wrapped up their case Wednesday and ceded the floor to the defense, which is attempting to convince a jury that the group never planned to actually execute their plot to kidnap the governor and instead just were talking tough.
The reported threats aren't expected to delay the trial, Schneider said.