How FBI tracked an ISIS-linked teen, stopped him from carrying out Mall of America mass shooting

The FBI arrested an 18-year-old Minnesota man on Tuesday after nearly two years of tracking him over an alleged plot to carry out a mass shooting at the Mall of America near Minneapolis.Sheikhdoon Abdullahi Mohamud was taken into custody after an undercover FBI agent allegedly sold him an AK-47, ammunition and magazines for $600, according to the criminal complaint.Investigators allege Mohamud told the undercover informant that he planned to use the weapon to kill between 30 and 60 people at an event at the mall in late October.A nearly two-year investigationAccording to a court document posted by the US department of Justice, the FBI had been investigating Mohamud since about December 2024. Over roughly 21 months, the department says, Mohamud and a confidential human source exchanged hundreds of messages across social media and encrypted messaging platforms.According to the document, those messages were ones "wherein MOHAMUD expressed his desire to travel to Somalia to join a Foreign Terrorist Organisation (FTO) and fight on its behalf and/or to commit a mass-casualty attack on behalf of an FTO in Minnesota by acquiring and using a firearm and ammunition".The contact began in or about December 2024, the department said, when the source, referred to as CHS1, started exchanging messages with Mohamud. The two communicated directly on the encrypted appsTelegram and Signal, and on the social media platforms Discord and TikTok. On Signal, the document notes, Mohamud used the account "Mister Miser".Mohamud allegedly told the source across various platforms that he wanted to travel abroad to fight for al-Shabaab, a designated foreign terrorist organisation. He said that, if he could not go, he would carry out a mass shooting instead. He later said he wanted to join ISIS.He also reportedly was in favour of the man who drove a truck into a crowd in New Orleans on January 1, 2025, killing 14 people.In July, Mohamud allegedly said he intended to kill 30 to 60 people at the Mall of America as the owners were Jewish and said he wanted to kill non-Muslims.Mohamud reportedly told the informant he had planned the attack for October 24 because a "Hmong Arts Celebration" was being held at the mall that day.The Mall of America is the largest shopping centre in the United States, with over 500 stores.You use AI every day. Now get your AI Quotient. Take the AIQ test.