MINNEAPOLIS — An FBI agent offered greater detail about the man charged in the thwarted terrorism-inspired attack at the Mall of America, describing how his pro-ISIS social media posts triggered their investigation into what they allege was a plot to kill “as many people as possible.”

After hearing the testimony during a Monday detention hearing, U.S. Magistrate Judge Dulce Foster ruled there was enough evidence to keep 18-year-old Sheikhdoon Abdullahi Mohamud held in the Sherburne County Jail on his charge of knowingly receiving a firearm and ammunition to be used in a federal crime of terrorism.

Foster said it’s “impossible to understate” the seriousness of a defendant’s desire to shoot up a public place.

The hearing in Minneapolis heavily focused on prosecutors’ allegations of Mohamud as a man who, at several times through his conversations with a confidential source, stated his hopes of carrying out a terrorism-inspired mass casualty attack overseas, and then in Minnesota. The allegations were countered by Mohamud’s defense attorneys, who described their client as a man with no criminal history who was influenced by a paid FBI informant leading up to his purchase of the weaponry.

Mohamud sat in a yellow jail T-shirt and pants and did not speak as attorneys for both parties discussed the allegations against him. He was arrested nearly two weeks ago after federal prosecutors said he purchased an AK-47 rifle, four magazines and 200 rounds of ammunition from an undercover officer at a parking lot in Richfield.

Keegan Rupenthal, a counterterrorism agent with the FBI, testified that Mohamud first came on investigators’ radar in December 2024 after they were flagged to pro-ISIS videos he posted on TikTok. He said the teen initially told the informant through various online platforms that he wanted to travel to a region in Somalia with an ISIS stronghold in hopes of fighting alongside the terrorist organization and dying.

Rupenthal said Mohamud, a U.S. citizen, said he would hide the true intent of his travels from his family by telling them he was going to Somalia for a job. Rupenthal said the agency’s attempts to talk to Mohamud’s family were unsuccessful when they were told to speak to his attorney. Rupenthal said Mohamud then visited his family in Ohio during the summer, where they took away his phone when they saw the “concerning” messages on his device.

Mohamud’s plans to fight overseas eventually changed, Rupenthal said, when he couldn’t get enough money to travel to Somalia. He then turned to planning an attack locally, and fixated on doing so at a festival at the Mall of America on Oct. 24.

“He wanted to harm as many people as possible,” Rupenthal said on the stand.

Assistant U.S. Attorney Benjamin Bejar asked what he specifically meant by harm.

“He wanted to kill them,” Rupenthal replied.

Manny Atwal, Mohamud’s federal defender, pressed the agent on the fact that the FBI’s involvement with her client began when he was underage, at 16 years old, and how agents did not attempt to intervene sooner despite their claims of Mohamud expressing his desire to commit a mass casualty event at several times over the nearly two-year investigation.

“Despite his words that he used about doing things to people right here in Minnesota and in the United States, nobody came to talk to him,” she said.

She asked the court to release her client on constant GPS monitoring with no access to internet devices while he awaits trial.

Atwal also argued that Mohamud was influenced by the FBI informant, saying he had never expressed a desire to handle a firearm until their 22-month conversation. She pointed to a message between the pair in which Mohamud said “I’m not going to lie you did help encourage me a little bit in 2025 when I said I’ll do hijrah at 18 years old.”

Rupenthal said that Mohamud told investigators after his arrest that he’s had a desire to die and commit some kind of violence since he was 15 years old. Atwal countered that her client didn’t take those desires seriously until he turned 16, at which point the FBI informant “was placed into his life.”

In explaining her decision to jail Mohamud further, Foster pointed to his long desire to kill himself or others and the risk of him fleeing before his trial.

“This is not just an act of a teenager who is discussing his desire to participate in a jihad in the theoretical sense,” Foster said.

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