I've seen this before. A Muslim terrorist slays a non-Muslim citizen in the West, and representatives of the Muslim community rush to dissociate themselves and their faith from the horror. After British soldier Lee Rigby was hacked to death last week in Woolwich in south London, Julie Siddiqi, representing the Islamic Society of Britain, quickly stepped before the microphones to attest that all good Muslims were "sickened" by the attack, "just like everyone else."

This happens every time. Muslim men wearing suits and ties, or women wearing stylish headscarves, are sent out to reassure the world that these attacks have no place in real Islam, that they are aberrations and corruptions of the true faith.

But then what to make of Omar Bakri? He too claims to speak for the true faith, though he was unavailable for cameras in England last week because the Islamist group he founded, Al-Muhajiroun, was banned in Britain in 2010. Instead, he talked to the media from Tripoli in northern Lebanon, where he now lives. Michael Adebolajo—the accused Woolwich killer who was seen on a video at the scene of the murder, talking to the camera while displaying his bloody hands and a meat cleaver—was Bakri's student a decade ago, before his group was banned. "A quiet man, very shy, asking lots of questions about Islam," Bakri recalled last week. The teacher was impressed to see in the grisly video how far his shy disciple had come, "standing firm, courageous, brave. Not running awSome refuse even to admit that this is the question on everyone's mind. Amazingly, given the litany of Islamist attacks—from the 9/11 nightmare in America and the London bombings of July 7, 2005, to the slayings at Fort Hood in Texas in 2009, at the Boston Marathon last month and now Woolwich—some continue to deny any link between Islam and terrorism. This week, BBC political editor Nick Robinson had to apologize for saying on the air, as the news in Woolwich broke, that the men who murdered Lee Rigby were "of Muslim appearance."

Memo to the BBC: The killers were shouting "Allahu akbar" as they struck. Yet when complaints rained down on the BBC about Mr. Robinson's word choice, he felt obliged to atone. One can only wonder at people who can be so exquisitely sensitive in protecting Islam's reputation yet so utterly desensitized to a hideous murder explicitly committed in the name of Islam.