FBI arrests 18-year-old Sheikhdoon Abdullahi Mohamud after a nearly two-year investigation into an alleged ISIS-inspired plot to carry out a mass shooting at the Mall of America.

The FBI has arrested 18-year-old Sheikhdoon Abdullahi Mohamud after a nearly two-year investigation into an alleged plan to carry out a mass-casualty attack at the Mall of America in Minnesota.

Federal authorities said Mohamud was taken into custody Tuesday in Richfield after allegedly purchasing an AK-47-style rifle, four magazines and 200 rounds of ammunition from an undercover FBI employee whom he believed was connected to ISIS. Prosecutors said he paid $600 for the weapons and ammunition. 

According to court documents, the FBI investigation began in December 2024, when Mohamud allegedly began communicating with a confidential source. Authorities say he initially expressed interest in traveling to Somalia to fight for a terrorist organization but later shifted his focus toward carrying out an attack in Minnesota. 

Prosecutors allege that Mohamud eventually identified the Mall of America as a potential target. He reportedly discussed carrying out the attack during the Hmong Arts Celebration scheduled for October 24, a day when officials say he expected large numbers of people to be present. 

U.S. Attorney Daniel Rosen said investigators intervened before Mohamud could carry out the alleged plan. Authorities said he had expressed an intention to kill between 30 and 60 people, according to the allegations in the criminal complaint. 

The arrest came during an undercover operation in which the FBI source posed as an ISIS associate. After Mohamud allegedly completed the purchase and left the meeting with the weapon and ammunition, FBI agents arrested him, authorities said. 

FBI officials said the case demonstrates the role of a lengthy investigation in identifying and disrupting an alleged threat before it could develop into an attack. Mohamud appeared in federal court in St. Paul following his arrest. 

The allegations have not been proven in court. Mohamud is presumed innocent unless and until he is found guilty.