If the government has a clear strategy in its prosecution of four men accused of scheming to kidnap Michigan's governor, it might succinctly be described as shock and awe.

On the fourth day of testimony in a trial expected to last as long as six weeks, federal prosecutors called one of their most critical witnesses, Dan Chappel, a confidential informant who spent months recording seemingly every meeting he had with the defendants.

Chappel, a former Army sergeant who was known publicly only as Big Dan, testified for four hours about what he saw and heard. Prosecutors say that Adam Fox, Barry Croft, Daniel Harris, and Brandon Caserta were involved in a plan to spirit the governor away from her vacation home in northern Michigan. Chappel said the men wanted to get the governor and start a civil war.

His testimony followed on the heels of that of an undercover FBI agent, who took the stand Thursday and said that he had approached Fox in June 2020 because of a concern he was planning to take.

The testimony of the two FBI assets, and especially the evidence they helped prosecutors present, brought startling and often harrowing new details to the allegations.

On Friday alone, prosecutors showed some 80 exhibits, which included audio recordings, videos, photographs, and text messages that were used to portray the accused as highly motivated to commit violent acts against politicians.

Fox was heard on tape fantasizing about having the governor hog-tied on a table, just hours after conducting a daytime surveille of her lakeside cottage with Chappel and one other person. After dinner following a field training exercise in Wisconsin, Croft is heard talking about the need for violence.

On a recording made by Chappel at a diner, Croft says that he doesn't like seeing anyone get killed.

Harris could be heard proposing to knock on the door of Whitmer and Caserta could be heard saying that they were going to shoot her.

In photos and videos projected in the courtroom, the defendants could be seen participating in armed training sessions and on the run near the governor's lakeside cottage. Chappel and two FBI agents recreated the path the defendants allegedly planned to use to get to Lake Michigan.

The four defendants and some members of their families sitting in the gallery silently watched as the defense attorneys were unable to slow the onslaught or attempt to mitigate the damage. When they have the chance to cross-examine Chappel, they will claim their clients are innocent.

First, that the defendants' words were allowable under the principles of free speech, and second, that they were never attached to anything close to a finalized plan.

They claim that the defendants were entrapped by the FBI, in particular, Chappel and Stephen Robeson. They argue that the defendants were brought together, encouraged and amplified their anti-government feelings, and even suggested actions they could take, urging them to do things they otherwise would not have done.

The version of events described by Chappel will be important for the defense to chip away at. Defense attorneys have described him as the intellectual engine of the entire scheme, someone who used his status as a combat veteran to win the trust of the defendants and even discuss acquiring explosives.

In a parallel case in a Michigan state court, eight other men are charged with providing material support to terrorism. Defense attorneys pored over his testimony to look for inconsistencies that could undermine his credibility, even though his true identity was not revealed. Chappel received $54,000 from the FBI in payments and for expenses that included a new laptop, phone, and an Apple Watch.

Defense attorneys noted that he had changed his appearance, shaving a beard he had worn while spending time with Fox and accompanying him and others on a September surveillance run to the house. That was a small point to make since one of the defendants, Croft, had done away with his facial hair prior to trial, something prosecutors had taken pains to note to the jury earlier.

He adopted the fake name Mark Woods and relied on another FBI agent to get in touch with Fox.

After jury selection and two days of testimony last week, the trial hit an unexpected speedbump when a critical participant in the trial tested positive for COVID-19 last weekend, forcing Judge Robert Jonker to halt proceedings for three days. He didn't name the person who tested positive.

The trial could be pushed into April. The government planned to bring 40 witnesses after testimony was finished, according to the lead prosecutor.

Chappel was the government's fourth witness, so the jury will hear from more witnesses before the defense attorneys can make their own case. Two former defendants who pleaded guilty and agreed to cooperate with the prosecution are among the most critical government witnesses.

Their testimony could start on Tuesday.