A 17-year-old boy stabbed a girl with a piece of glass at a secondary school after posting on social media that he had received "a calling from the Lord Jesus Christ", a court has heard.
Sheffield Crown Court heard the 17-year-old - who cannot be named for legal reasons – attacked members of Birley Academy after announcing he would do “what God Almighty thinks necessary” online.
A consultant psychiatrist told the jury he believed the teenager had been experiencing a “psychotic episode” at the time of the incident.
In a Reddit post read in court on Tuesday, the suspect said "Mrs [staff member's name] if you still work there, don't come in today”and “[Another staff member's name] I haven’t f****** forgotten you either. Absolute traitor.”
A second post on the Reddit Birley Academy page said: "Today is the day. A calling from the Lord Jesus Christ has been cast upon me. To do what God Almighty thinks is necessary."
The jury heard how the teenager had armed himself with shards of glass before entering the school and attacking staff and pupils on 1st May.
The boy is accused of three counts of attempted grievous bodily harm with intent, which he denies.
He has previously pleaded guilty to unlawful wounding and possession of a sharply pointed object on school premises.
Prosecutor Katy Rafter told the court that the boy had warned another teenager to “stay away” from the school that day via Snapchat, stating that the school “was done for” and he would be “arrested afterwards, in jail or dead.”
She told the jury: "[The other boy] thought he was joking. He was not joking. Having armed himself with pieces of broken pieces of glass, he walked from his home address to Birley Academy."
Concerned by the online posts, members of the public alerted both the school and the police.
CCTV footage shows the defendant arriving at the school at 08:48 GMT. The court heard that he requested to see a member of staff at reception who had not yet arrived, before proceeding to attack a 12-year-old girl who had entered the area with two friends.
Rafter said: "Almost immediately, without warning or provocation, he stabbed her, [the girl] intending to smash the broken glass into her."
The receptionist and a youth mentor who sought to intervene were also attacked, while the girls hid in the toilet after finding the classrooms had been barricaded.
Upon his arrest, the boy made remarks about "accepting Jesus Christ as your Lord and Savior," and later claimed he had mental health issues.
The court was also informed that neither of the staff members mentioned by the teenager in his social media messages could recall any prior incidents with him.
A psychiatrist told the court that the defendant had received a diagnosis of autism and was thought to have been experiencing a psychotic episode on the day of the incident.
The trial continues.
