On April 13th Mr Khan was pulled from the room by a crowd of fellow students. The violence that followed, partially recorded on a mobile phone, was staggeringly brutal. The attackers shot Mr Khan twice, dragged his corpse through hallways, beat it with planks and stripped it naked.
Earlier in the day a fellow journalism student had accused Mr Khan of blasphemy. That allegation appears to have triggered the attack. The penalty for blasphemy under Pakistani law is death. But it is increasingly common that vigilantes take the law into their own hands before courts get involved. At least 65 people have been murdered by mobs for allegedly insulting Islam since 1990. As often in such cases, there was no evidence against Mr Khan, apart from the claims of the classmate who denounced him, Wajahat, a disgruntled young man with a fondness for the blood-curdling rhetoric of Islamist televangelists.
Horrible story, especially because everyone seems complicit with this. Young, well-educated students, elderly religious conservatives, the government, the courts, the military, the intelligence services...radical Islam has become an integral part of Pakistan.
The participation of so many students in Mr Khans murder is a sign of growing religious intolerance on campuses. Pakistans Islamist parties have been fanning the flames of it: since the assassination in 2011 of Salman Taseer, a governor of Punjab who had pushed for reform of blasphemy laws, support for the current ones appears only to have grown.