Federal authorities arrested an 18-year-old Minnesota man accused of planning an ISIS-inspired mass shooting at the Mall of America after an undercover FBI operation allegedly supplied him with an AK-47 and 200 rounds of ammunition.

Sheikhdoon Abdullahi Mohamud was arrested Tuesday after allegedly obtaining the rifle and ammunition from an FBI confidential source and discussing plans to attack a festival at the Mall of America in Bloomington, Minnesota, according to a federal criminal complaint unsealed Wednesday.

Prosecutors allege that Mohamud had been under FBI investigation since December 2024, when a confidential source began communicating with him about either traveling to Somalia to fight for the al-Shabaab terrorist organization or carrying out a mass-casualty attack in the United States.

According to court documents, Mohamud eventually shifted his focus toward an attack inside the United States and expressed support for ISIS. Investigators say he discussed carrying out a shooting at the Mall of America and indicated that he wanted to kill between 30 and 60 people.

Prosecutors allege that Mohamud specifically targeted the Mall because he believed it was owned by Jewish people. He also allegedly expressed anger over what he described as the mistreatment of Muslims following a May attack on an Islamic center in San Diego.

Mohamud allegedly discussed several possible targets and drew inspiration from previous mass attackers, including the 2022 New Orleans attacker and Omar Mateen, who killed 49 people at the Pulse nightclub in Orlando in 2016.

By August, investigators say Mohamud had begun arranging a meeting with the confidential source to obtain a firearm. The two eventually agreed to meet Oct. 6, when the undercover source allegedly provided Mohamud with an AK-47, four magazines and 200 rounds of ammunition.

Authorities say Mohamud had discussed carrying out the attack Oct. 24 during the Hmong Arts Celebration at the Mall of America. After receiving the weapons, he was arrested by FBI agents as he exited the vehicle.

Federal prosecutors described the investigation as a nearly two-year counterterrorism operation that prevented the alleged attack before anyone was injured. U.S. Attorney Daniel Rosen said the investigation allowed authorities to detect and disrupt the threat before Mohamud could carry out what he allegedly described as an attack that could kill dozens.

FBI Special Agent Christopher Dodson said the messages investigators uncovered showed an alleged commitment to ideologically motivated violence and hatred toward people of other faiths.

Mohamud faces a federal charge alleging that he knowingly received a firearm and ammunition while knowing or having reason to believe they would be used in a felony or federal crime of terrorism. He is presumed innocent unless proven guilty in court.

Rosen also said the FBI had previously attempted to warn Mohamud's parents after investigators became aware of extremist material he was sharing online. The U.S. attorney urged parents to take seriously any warning from federal authorities that a family member may be undergoing radicalization.

The arrest comes as federal authorities continue investigating and disrupting alleged ISIS and other terrorist plots inside the United States. In this case, investigators say the intervention stopped an alleged mass-casualty attack at one of the country's most heavily visited shopping destinations before it could take place.