A 17-year-old boy who stabbed a "predatory paedophile" school worker at his home in east London has been cleared of murdering him.
The boy stabbed Muhammad Amirul Haq, 27, at his home in Poplar last November fearing the student support officer may rape or kill him, the Old Bailey heard.
The victim, known as Amir, was married and "outwardly religious" but was secretly bisexual, the jury heard.
The boy, who cannot be named, has been cleared of murder and manslaughter.
Tower Hamlets Council said it would now look into further allegations against Amir, who worked at St Paul's Way Community School.
Judge Jeremy Roberts said: "It was tragic for everybody that it happened in these circumstances."
The jury heard the victim had invited the defendant and another boy to his home to smoke shisha pipes and had shown them pornography and had proposed to carry out sex acts on them.
The defendant said he was armed in case the victim forced him into "sexual acts" and had asked the older man to "back off".
'Signs of respectability'
The knife fatally injured the school worker when he "lunged" at the "devout, humble Muslim" teenager, the court heard.
The boy told the jury: "I genuinely thought that he would either rape me or if I refused he would kill me.
"I produced the knife. As he was holding my arm I brought it out and held it in front of me.
"He said 'help me this time and you can leave'. I told him to back off and let me go.
"He said 'what are you going to do?, there is nothing you can do, no-one will believe you'. He lunged towards me."
Defence QC Brian O'Neill said: "Amir displayed all the outward signs of respectability.
"He had an arranged marriage, he wore a religious hat and sported a beard. He went to mosque and prayed and encouraged others to do the same.
"But all of that was a sham.
"The truth was that Amir was a predatory paedophile who preyed on young boys in his own community and groomed them in order that he might sexually assault and rape them."
Victor Temple QC, prosecuting, argued the boy was being "vengeful" and "knew full well what he was doing".
Tower Hamlets council said: "Prior to this court case, neither the council or the school had received any allegations of improper conduct.
"We will now be looking into the allegations that have come to light during this court case.
"We can confirm that all appropriate checks were in place prior to Mr Haq's employment."