In a hint of showdowns to come, defense lawyers for three men accused of conspiring to join ISIL hammered away at the credibility of a key government witness on Monday.

The cross-examination appeared to rattle Abdullahi Yusuf on his second day of testimony as the federal trial in Minneapolis resumed.

Yusuf, 20, spent much of Friday describing his recruitment by Guled Omar, 21, into a group of Twin Cities Somali-American men and told jurors how Abdirahman Daud, 22, and Mohamed Farah, 22, helped him along the way.

On Monday, Yusuf's admitted history of lying to authorities triggered intense scrutiny by the defense.

"Why should we believe anything you say?" asked Glenn Bruder, Omar's attorney.

"Because it's the truth," Yusuf said.

"And we're supposed to regard you as trustworthy despite your history of lying?" Bruder said.

Yusuf had said he first tried to cover for his "former friends" in his initial interviews with FBI agents after agreeing to cooperate in the investigation in early 2015. He said Monday that he tried to put as much blame as he could on fellow conspirators Abdi Nur and Yusuf Jama because they had already gone overseas.

Yusuf was confronted over several misstatements from previous testimony, at one point being read back a transcript from Friday's statements.

Bruce Nestor, Daud's attorney, pointed out that Yusuf first said it was Nur who gave him phone numbers of ISIL members who could help him reach Syria once he arrived in Turkey. But after Daud's April arrest, and a meeting with FBI agents in which they accused Yusuf of withholding information, he said it was Daud who gave him the numbers and also recommended using encrypted social media.

"You can cut it whichever way you want, but Abdirahman Daud gave me those two phone numbers," Yusuf said.

The three men each are charged with conspiracy to provide material support to ISIL and to commit murder outside the United States on behalf of the terror group, which carries a possible life sentence. Yusuf was the first of six to plead guilty in the investigation.

Each time Yusuf changed his account to authorities, they went from "statements that didn't help the government build its case to those that did help the government build its case," Bruder said Monday.

"By helping the government, you thought the changes might benefit yourself," Bruder said. "[Yet] when it's in your self-interest you have a history of lying. … You expect us to believe you anyway?"

"Yes," Yusuf said.

The name of Amir Meshal also surfaced throughout Monday's testimony. Mohamed Farah's attorney, Murad Mohammad, first asked Yusuf if he knew Meshal, a 32-year-old American of Egyptian descent whose interactions with youths at a Bloomington mosque prompted the mosque's director to contact authorities. Yusuf said Meshal was close with Nur and held radical views about Islam. He said Meshal also had conversations with other men charged in the case, including the three on trial. At first, he said, the group thought Meshal's views were too harsh and that perhaps he was working for the government in an attempt to entrap people.

"I would say in spring 2014 our views aligned," Yusuf said.

Yusuf said a weekly religious studies group that Omar led included Meshal and once met at his home in April 2014. But he later said Meshal was not part of the plot to go to Syria.

Defense attorneys quizzed Yusuf multiple times about a fall 2014 paintball session in Lakeville that he has said he believed was preparation for battle. Yusuf told attorneys Monday that the friends' use of tactical "military" maneuvers while shouting "Allahu akbar" — or "God is great" in Arabic — during the game seemed unusual.

"We were doing more than having fun," Yusuf said.

Yusuf was the first of three star witnesses prosecutors will call during the trial. Later this week, Abdirizak Warsame, an Eagan man who pleaded guilty to conspiracy in February, is expected to testify. Abdirahman Bashiir, an uncharged conspirator who later became a paid informant, is also expected to take the stand.

A Minneapolis park police officer, an immigration officer and an FBI joint terrorism task force officer also each took the witness stand Monday afternoon. An FBI task force officer will return Tuesday to continue testimony about searching Nur's car shortly after he disappeared.

Twitter: @smontemayor