A German expert on de-radicalizing terrorists on Tuesday offered the most extensive public look yet at the nation's first attempt to evaluate six young Minnesota men convicted of plotting to join ISIL. The six will be sentenced in November.

Daniel Koehler, who was hired to help federal court officials assess the risk of Minnesotans convicted of trying to join the Islamic State in Iraq and the Levant (ISIL), began two days of testimony Tuesday in Minneapolis by taking at-times heated questioning from four defense teams about his findings.

Koehler personally evaluated six defendants who pleaded guilty before the May trial of three others in the case. U.S. District Judge Michael Davis, who hired Koehler, said Tuesday that the program was his attempt to gather more information before sentencing terror defendants, adding: "My job is to make sure the community is safe."

"This is not a misdemeanor traffic ticket that they can pay and get out and go play basketball," Davis said. "People should get that out of their minds."

Attorneys for Abdullahi Yusuf, Abdirizak Warsame, Zacharia Abdurahman and Hamza Ahmed questioned Koehler on Tuesday. The cases of two others — Hanad Musse and Adnan Farah — are expected to be discussed on Wednesday.

Of the four so far, Koehler said Warsame posed the highest risk. Warsame was arrested in December 2015, months after six others were arrested in a series of FBI raids.

Though Warsame, like Yusuf, quickly began to cooperate with the government and testified at trial, Koehler said the defendant downplayed his role as emir, or leader, of the group in an interview with the expert.

Warsame's attorney, Robert Sicoli, was among those who criticized the open-ended nature of Koehler's questions to the defendants, which Koehler said was intended to gather their stories in their own words.

Koehler meanwhile factored any omissions of key details into his risk assessments.

Koehler said Warsame's April interview had to be briefly paused when he broke down after acknowledging that he could have been killed in Syria.

Warsame was the only man indicted in the case who never tried to travel abroad.

"He was expressing to you that he had a change of mind, he had a change of heart," Sicoli said.

In her questioning, Manvir Atwal, a federal defender who is one of two attorneys representing Yusuf, nodded at a mentoring program that is already being offered to her client through the nonprofit Heartland Democracy — widely considered the nation's first jihadi rehabilitation attempt.

Koehler said he assessed Yusuf as being "medium-to-low risk" and recommended an early-release counseling program. The question, Koehler said, is whether the United States has the right sort of counseling and prison services to intervene.

Koehler said the United States is "about 20 years" behind Europe in developing programs to counter homegrown violent extremism. And he said the country's lack of prison counseling and appropriate religious services was a "predicament" for him as he makes recommendations to the federal court system.

"What is being done for that person in the prison, that changes my whole assessment," Koehler said. "If nothing's being done, those … years in prison are the black box."

Attorneys spar with expert

Koehler testified on the same day the FBI announced that its Joint Terrorism Task Force would be taking over the investigation into Saturday's knife attack at St. Cloud's Crossroads mall. Koehler told a prosecutor that his assessments weren't limited to attempts to leave the country.

"You know better than anyone in this courtroom that terror groups like ISIL encourage individuals to commit violent acts where they are" if they are unable to travel, said John Docherty, assistant U.S. attorney.

JaneAnne Murray, an attorney for Ahmed, later sparred with Koehler over his "medium to high" risk assessment of her client after a Skype interview late last month. Koehler said Ahmed was not forthcoming about frequent social media posts proclaiming his desire to be martyred and cheering ISIL over Al-Qaida as if they were rival sports teams. He also spent little time addressing the departure of his brother Shahir years earlier, despite posting online that he believed his brother left to fight abroad.

Murray pushed back, asking if a handwritten statement of accountability was not enough of a sign that Ahmed wasn't hardened in his beliefs.

"Which is why he is medium to high risk — not high risk," Koehler said.

" 'To be honest, being stopped by the FBI was the best thing that happened to me,' " Murray continued, reading from his letter. "Do you not think that's heartfelt?"

"I do," Koehler said, "which is why he is medium to high risk."

" 'I want to hold and hug my parents and siblings again,' " Murray continued reading. "That simply lowers the risk from high to medium high?"

Stephen Montemayor • 612-673-1755

Twitter: @smontemayor