A National Investigation Agency court in Kerala on Wednesday convicted six persons in a 2010 case of chopping off the hands of a professor for allegedly insulting Prophet Mohammed in a question in an examination paper., Live Law reported.

On July 4, 2010, the right hand of TJ Joseph, a professor at the Newman College in Thodupuzha of Idukki district, was hacked off allegedly by members of now-banned Islamic outfit Popular Front of India.

Joseph, the head of the Malayalam department at the college, had selected a passage from a short story by filmmaker PT Kunju Muhammed to test students on punctuation. The passage carried an imaginary conversation between god and a “mad man”. The professor had renamed the “mad man” as Muhammed, sparking a controversy.

The assailants attacked Jospeh while he was returning home from a church in Ernakulam district’s Muvattupuzha. The attackers dragged the professor out of his vehicle and assaulted him. His hand was chopped off by main accused Ashamannur Sawad, who is still absconding.

Special NIA court Judge Anil K Bhaskar on Wednesday passed his verdict on the second phase of the trial in the case.

He held six persons guilty of attempted murder, conspiracy and various other offences under the Indian Penal Code and under the stringent Unlawful Activities (Prevention) Act. The judge, however, acquitted five accused persons citing lack of evidence.

During the first phase of the trial, 31 accused faced prosecution. Of these, the court had convicted 13 men and acquitted 18 others in 2015, PTI reported.

Former Kerala Police chief Jacob Punnoose told the BBC that it was “the most well-organised attack” that he had investigated in his career.

“So much planning went it to it,” the retired officer added. “The victim was identified, the place of attack was selected, every precaution was taken. Three vehicles, including two getaway cars, were used.”