He said they disrespected his Islamic faith during a sleepover. Then, he stabbed a 13-year-old 49 times.

A 17-year-old Muslim convert read his Quran for encouragement during a sleepover before he stabbed his friend’s brother to death.

Now, he will remain behind bars for the rest of his life.

This month, Palm Beach County Judge Cheryl Caracuzzo sentenced Corey Johnson to three life sentences for the stabbing death of 13-year-old Jiovanni Sierra. Johnson was found guilty and convicted by a jury of murder and two counts of attempted murder.

On March 12, 2018, police responded to a distress call at the BallenIsles Country Club in Palm Beach Gardens in Florida. The defendant had been invited to a sleepover with other children and family friends at the home of Elaine Simon, 43, and her son, Dane Bancroft, 13.

A couple of hours earlier, Johnson had been invited to the celebration of Jiovanni’s 13th birthday party. Johnson’s invitation to the event was because of his friendship with Dane Bancroft’s older brother, Kyle Bancroft.

The boys opted for a sleepover at Simon’s home, where the defendant claimed the victim disrespected his newly adopted Islamic faith. Johnson told investigators he read the Quran on his phone for encouragement before stabbing Sierra 49 times while he slept and slashed his throat.

Then, the defendant stabbed Simon and Dane Bancroft. However, they survived the ordeal.

According to prosecutors, Johnson was known among his friends and classmates as an ISIS sympathizer who shared the ideological values and support for the KKK and made antisemitic remarks against Jews. Johnson had been a known entity to law enforcement due to his actions before the fatal incident. In 2016, the defendant had made threats on social media against a Catholic High School in Doncaster, England. Up to 100 students withdrew from the school for fear of an imminent attack.

“We have our sights set on you, and by Allah we will kill every infidel student at this school inshallah) #McAuleySchoolMassacre,” stated Johnson on an Instagram account, according to the Daily Mail.

Soon, a joint investigation between the FBI and a European counter-intelligence unit ensued.

Then, in 2017, the FBI initiated another investigation and contacted William T. Dwyer High School authorities after the defendant reached out to ISIS online to join the organization. Johnson committed the homicide a few weeks before the FBI was able to issue a probable cause affidavit against him in relation to his ISIS case.

Johnson’s defense lawyer claimed the defendant’s violent behavior stemmed from a family history of depression suffered by his parents and his exposure to the physical abuse of his mother by his father.

"I attacked people who were like a second family to me. I ruined a decade-long friendship, I caused distress to my own family who I love more than anything and worst of all I took the life of an innocent 13-year-old boy in the most heinous, cowardly way possible," Johnson said to the judge before he was sentenced, according to WPBF 25 News.

However, the defendant’s plea did not convince Caracuzzo, who remained adamant in her belief that Johnson was insincere.

"I do not think rehabilitation is likely," said Caracuzzo, who denied the defendant’s plea for a 45 sentence with a possibility of parole, according to The Palm Beach Post.

Johnson’s grandparents disagreed with the sentencing. Nevertheless, they hugged Sierra’s mother before departing the courtroom.