MINNEAPOLIS (WCCO) — A key prosecution witness in a Twin Cities terrorism trial repeatedly admitted lying to FBI agents and prosecutors in order to get a more lenient sentence.

Three defendants — Abdirahman Daud, Mohamed Farah, and Guled Omar — are on trial in federal court in Minneapolis accused of trying to join ISIS.

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Abdulahi Yusuf, 20, repeatedly testified he was cooperating with the government in the hope of getting a lighter sentence. He has already entered a guilty plea in the case.

Defense attorneys tried to poke holes in Yusuf’s testimony, hammering at his credibility.

Yusuf is one of six of the original ten defendants who have pleaded guilty in the case. The remaining three defendants who are on trial in federal court in Minneapolis all face possible life terms.

Under cross examination by Bruce Nestor, the defense attorney for Abdirahman Daud, Yusuf seemed to waver about who had provided him key information about how to contact ISIS fighters.

At first Yusuf testified Abdi Nur had given him the contact information including phone numbers. Then Yusuf testified it was in fact Daud who had given him the information.

Abdi Nur is one of the ten defendants charged in the case and the only one who is known to have made it to Syria. Nur is widely believed to have died fighting for ISIS.

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Under a withering cross-examination by Glen Bruder, the defense attorney for Mohamed Farah, Yusuf was asked, “When it’s in your best interest you have a history of lying.”

Yusuf replied, “Correct.”

Bruder then asked,  “But you expect all of us to believe you always?”

Yusuf replied, “Yes.”

He acknowledged telling federal agents that one of the defendants — Guled Omar — “partied a lot” and was often “high as hell.” But on the stand he admitted he had never seen him smoke marijuana. Yusuf also testified when he and Guled Omar and he were both housed in the Anoka County Jail he reported that Omar had threatened him and his family. Jail officials were able to determine Guled Omar could not have made the threats. On the stand Yusuf described it as a case of “mistaken identity.”

Prosecutors still appear to have a number of other cards in their hand, most notably secretly taped recordings by another member of the plot turned government informant. The government plans to call that witness and play those recordings later in the trial, which is expected to last at least another two weeks.

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Yusuf and the others who pleaded guilty face 15 years in prison. The three men on trial face a maximum of life in prison.