A key informant in the government's case against a group of young Twin Cities men accused of conspiracy to support ISIL was arrested last week on probable cause of illegally possessing a handgun, according to court documents filed this week.

He was released the next day, pending the filing of charges.

Abdirahman Abdi Rashiid Bashiir, 20, was at a Minneapolis apartment visiting friends late Friday evening when a semiautomatic handgun discharged accidentally as he attempted to modify it, according to a source familiar with the investigation. One bullet lodged into the wall and no one was injured.

Police were notified and placed Bashiir under arrest. He was released from Hennepin County jail by 4 p.m. Saturday pending a criminal complaint, jail records show. According to a police report, officers recovered a firearm, magazines, shell casings, other rounds and a holster.

Reached by phone Tuesday, Bashiir said he couldn't comment on the incident but characterized it as "some kind of misunderstanding."

"It doesn't have anything to do with the other case or my involvement," Bashiir said, referring to the ongoing ISIL recruit case in which he has cooperated with federal authorities. "I'm still a U.S. citizen. Whatever I do, I don't get no special treatment."

FBI and U.S. attorney's office spokesmen declined to comment on the arrest.

Originally a co-conspirator along with a half-dozen friends who allegedly attempted to travel to Syria to fight with the Islamic State in Iraq and the Levant (ISIL), Bashiir instead turned informant in early 2015.

Bashiir moved with family to Minnesota from San Diego in 2012 and was reportedly seen back in California last summer. He said Tuesday he "was just kind of [in Minneapolis] on a little visit. I might not be here long."

Bashiir, who remains under FBI protection, said he was still trying to finish school and decide what to do about his future. He said that, at one point on Friday, he encountered a group of local Somali-American residents who recognized him, but both sides went their own way without incident.

He said Tuesday that he expected to be called to testify at the May trial of the case's five remaining defendants.

Attempt to join Al-Shabab

In a separate development this week, federal prosecutors alleged that at least some of the five Minnesota men set for trial in May on the ISIL charges had shown a previous interest in Al-Shabab, the terror group based in Somalia.

In court filings, the prosecutors say they want to show a jury evidence of a thwarted 2012 attempt by one to go to East Africa.

By the time authorities arrested Guled Omar and charged him and five others last April with conspiring to go to Syria to fight for ISIL, the 21-year-old had allegedly already made three failed attempts in three years to fight abroad. Late Monday, prosecutors filed a request to show a jury evidence he first tried to join the nearly two dozen local Somali-Americans who left for Al-Shabab since the late 2000s.

According to court documents, Omar helped drive two men to Minneapolis-St. Paul International Airport in July 2012, knowing that they planned to join Al-Shabab, and planned to follow them to Somalia a month later. His passengers, Mohamed Guled Osman and Omar Ali Farah, have each been charged with providing material support to a foreign terror organization and are considered fugitives.

Prosecutors also say Abdirizak Warsame, who pleaded guilty in February to plotting to support ISIL after being charged late last year, will tell jurors that Osman, also known as "Bashi," was an "inspiration to the Syrian travelers" and that Omar and co-defendant Abdirahman Daud pledged allegiance to him, promising to join him in Somalia.

Agents stopped Omar in August 2012 as he tried to board a plane for Kenya, where he allegedly planned to cross over into Somalia. Omar told them he was traveling to get married in Africa, according to court documents.

Glenn Bruder, Omar's attorney, said Tuesday that the attempted travel in 2012 was "perfectly legitimate" and that he planned to argue its relevance before trial.

"It would distract the jury from the focal point of the case, which is whether or not three years later [Omar] attempted to join ISIL," Bruder said. "What he's being charged with in this indictment involved actions in 2014 and 2015, not 2012, and that's what the jury should consider."

Incident shows intent

But in their filing, prosecutors said the 2012 evidence would be necessary to outline Omar's intent, should he argue that his later attempted trips to San Diego were "innocent in nature."

"All incidents involve evidence of attempted travel out of Minnesota with the goal of joining a designated foreign terrorist organization," Assistant U.S. Attorney Andrew Winter said in the filing.

The five remaining defendants — Omar, Daud, Hamza Ahmed and brothers Adnan and Mohamed Farah — are scheduled to stand trial beginning May 9.

At the heart of the case against them is where they allegedly set their sights after Omar's failed 2012 travel plans: Syria. Relatives stopped a May 2014 attempt by Omar to ride to California with a co-conspirator turned informant and Yusuf Jama, who pressed on with his plans to leave the country and hasn't been seen since. Agents again stopped Omar from boarding a flight to San Diego later that year, something he lamented in recorded phone calls with the informant.

"That's gonna be the worst image for me, bro," Omar allegedly said. "Like [expletive] you tried fifty times and it still don't work out. … Three times, the exact same thing."

Twitter: @smontemayor