The teen accused of murder and attempted murder in a Palm Beach Gardens stabbing was under investigation for terrorist threats by federal authorities, who planned to bring charges against him in the near future.
A Jupiter Police report states that as recent as March 1, the FBI had met with one of Corey Johnson's friends as part of its investigation. FBI agents told Jupiter Police that they were meeting with the Assistant U.S. Attorney to develop affidavits for Johnson's arrest and advised it would be coming in the next several weeks.
In January 2017, police and the FBI investigated several threats that the then Dwyer High School student made on Instagram to a Catholic school in England. Those threats were so severe in nature that up to 100 students were removed from the school fearing some sort of attack.
During the investigation, Corey Johnson's mother and grandparents told police that he was fascinated with dictators and their role in history, including Adolf Hitler, Joseph Stalin and Kim Jung Un.
They also advised police that he recently began discovering religion and stated that he owned a Muslim prayer cloth, a Kufi and had been studying the Quran.
The Palm Beach County Sheriff's Office received information that Johnson watched several ISIS videos and according to its report, Johnson said he supported ISIS and reached out to the group and wanted to join the terrorist organization.
The FBI was given consent to monitor Johnson's social media accounts and internet activity by mirroring his computer.
In March 2017, Johnson denied he had any affiliation with ISIS, but did state he was supportive of known terrorist Anwar al Awlaki.
FBI agents advised Johnson to cease all social media activities related to ISIS and any other terrorist organization. He was also advised to have no further communications with anyone associated with the Catholic school he threatened.
Jupiter police says they kept in contact with the FBI's Joint Terrorist Task Force and in May 2017, they received word from agencies in Europe that Johnson had made some more online posts, and based on these, the FBI was working with the United States Attorney to bring official charges against him.
On Monday, Feb. 12, 2018, Jupiter police made contact with agents from the FBI's Joint Terrorist Task Force, who advised that they had a meeting set up with the United States Attorney within "the next few weeks."
Johnson confessed to killing 13-year old Jovanni Sierra on March 12, 2018.
Corey Johnson remains behind bars at the Palm Beach County Jail.