Cameron Defends Security Services after Media Unmask 'Jihadi John'

Prime Minister David Cameron on Friday defended Britain's security services and vowed to defeat Islamic extremists after media reports named Islamic State executioner "Jihadi John" as London graduate Mohammed Emwazi.

"We will do everything we can with the police, the security services, with all that we have at our disposal, to find these people and put them out of action," Cameron said at news conference in Wales.

"All of the time they (the security services) are having to make incredibly difficult judgments and I think basically they make very good judgments on our behalf," he said.

As the Islamic State group militant believed to be responsible for beheading at least five Westerners was finally identified by media and experts, families of the hostages said they hoped it would lead to him being brought to justice.

"My only hope is that the revelation of his identity will lead to his arrest," Dragana, the widow of David Haines, told Agence France-Presse from her home in Croatia.

Haines' daughter Bethany, however, told British news channel ITV that victims' families would feel closure only "once there's a bullet between his eyes."

Britain's domestic spy agency MI5 came under scrutiny following the revelations about Emwazi, a Kuwaiti-born computing graduate who had lived in London since the age of six, 

Civil rights group Cage said MI5 had been tracking Emwazi, aged in his mid-20s, since at least 2009.

"MI5 blunders that allowed Jihadi John to slip the net," read a headline in the Daily Telegraph newspaper, while the Daily Mail asked: "On the MI5 watch list, so how could he escape to Syria?"

- 'MI5 blunders' -

Olivier Guitta, managing director of security and risk consultancy GlobalStrat, warned that British security forces lacked adequate resources to track all those who crossed their radar.

"You can follow a guy for one year, two years, he doesn't do anything so you have to drop it," he told AFP.

"To monitor one person you need 30 officers, so if you have in England a thousand people that are on your list, you need 30,000 officers. We don't have that."

A spokeswoman for Cameron's Downing Street office said it would not comment on "speculation" about the identity of 'Jihadi John'."

London mayor Boris Johnson meanwhile accused Cage of "an apology for terror" for blaming Emwazi's radicalization on his alleged detention and "harassment" by the British security services.

- Families hope for justice -

Cage, which published years of correspondence with Emwazi, said he had become radicalized following a post-graduation trip to Tanzania in 2009 when he was accused of seeking to join militants in Somalia.

It also alleged that MI5 had launched a failed bid to recruit him.

"It was incredible that people could stand up and pretend that somehow it was the fault of the security forces," Johnson said.

An acquaintance of Emwazi who worshiped at a mosque near his London home described him as a "strict" Muslim who prayed up to five times a day.

"We never saw him with any group or doing anything wrong in the area," he said.

"If he has been doing these things it's wrong. I am sure he was a good guy and we are surprised about this now."

In the gruesome Islamic State videos posted online, the masked executioner appears dressed all in black with only his eyes exposed, brandishing a knife while launching tirades against the West.

"Jihadi John", nicknamed after Beatle John Lennon due to his British accent, is believed to be responsible for the murders of U.S. journalists James Foley and Steven Sotloff, British aid workers David Haines and Alan Henning and American aid worker Abdul-Rahman Kassig.

He also appeared in a video with Japanese hostages Haruna Yukawa and Kenji Goto shortly before they were killed.