President Trump had openly encouraged right-wing protests of social distancing restrictions in Virginia, Michigan and other states with stay-at-home orders, right after his administration had announced guidelines for governors to set their own timetables for reopening their communities. Among his tweets were calls to "Liberate Michigan!" and "Liberate Virginia."
Ms. Yarmosky referred to the president's tweets in the statement from Mr. Northam's office and said that the "rhetoric coming out of this White House has serious and potentially deadly consequences." She added: "It must stop."
This month, the Michigan Supreme Court ruled that a 1945 state law Ms. Whitmer had been using to issue her emergency orders was unconstitutional and invalidated them. Most of the orders had been lifted on June 1, but after the ruling, emergency orders were issued through the health department, which kept in place mask requirements as well as limits on gathering sizes and business capacities.
On Tuesday, Mr. Trask also provided additional details about the alleged plans to kidnap Ms. Whitmer. One of the suspects, Adam Fox -- identified by Mr. Trask as one of the leaders of the plot -- spoke about a plan to take Ms. Whitmer out on a boat in the middle of Lake Michigan, and leave her stranded with the engine disabled so someone would have to "come rescue" her, Mr. Trask said.
The other alternative had been to take Ms. Whitmer to Wisconsin or another unspecified state and to put her on trial. The accused had referred to her as "a tyrant."
Last week, the authorities said the men were affiliated with an extremist group called the Wolverine Watchmen, which court documents called "an anti-government, anti-law enforcement militia group."
The group met many times for tactical and firearms training and practiced building explosives, the F.B.I. said, and spoke about attacking law enforcement officers.
Mr. Trask and the prosecutor mentioned several other men who were not arrested, but who they said were involved in the surveillance and the discussion of the plot, including one from Wisconsin.
The testimony also indicated that the participants were suspicious that government informants were monitoring or had infiltrated their group, changing encrypted messaging platforms and giving each other code names in hopes of escaping such surveillance.
At one point after a planning trip to case the governor's vacation home and the surrounding area, Mr. Fox asked that all the participants be scanned with a device that is supposed to identify if anyone was wearing a transmission wire or a recording device.
The effort apparently failed, Mr. Trask said, with the group eventually infiltrated by four informants or undercover agents who continued to document what the group was planning. The F.B.I. has more than 100 hours of secretly recorded audio acquired throughout the investigation, Mr. Trask said.
Sally Berens, a U.S. magistrate judge, denied bail for three of the defendants after their lawyers argued that the alleged plots were more "inflammatory rhetoric" than substance.
Although their weapons and training were not illegal, the men sought to overthrow the government by force, and interrupting one plot did not eliminate future efforts, Judge Berens said. "It is the plot along the way that is clearly very dangerous," she said, stressing that the men remained a danger to the community.
The detention hearing for Mr. Fox and Ty Garbin, two of the six men facing federal charges, is scheduled for Friday. A federal court in Delaware on Tuesday ordered Barry Croft, a Delaware resident who was arrested there, extradited to Michigan to face charges.