The family of Steven Sotloff, the US journalist beheaded in an Islamic State video, have said they have "full faith" that his alleged killer "Jihadi John" will be brought to justice - a day after he was identified as a Londoner called Mohammed Emwazi.
Speaking to Sky News, the family's spokesman Barak Barfi said: "They hope that he will be caught by American intelligence officials, brought to trial in the United States, and convicted for the crime of beheading their son.
"There's going to be no closure until these people are brought to justice. This is just one step in a long path. The Taliban were toppled in Afghanistan, al Qaeda was eradicated in Afghanistan, and we believe that one day, Islamic State's end will come.
"When that comes, people like Jihadi John will have nowhere to run."
Since the 27-year-old was unmasked as the frontman of IS, reaction from the families of the Western hostages killed in cold blood has been mixed.
The mother of James Foley, the first US journalist murdered by the militant group, has said she forgives "Jihadi John" - and described Emwazi's apparent involvement with the terror organisation as "an ongoing tragedy".
Diane Foley told The Times: "It saddens me, his continued hatred. He felt wronged, now we hate him - now that just prolongs the hatred. We need to end it."
Loved ones of David Haines, the British aid worker believed to have died at the hands of Emwazi, are also divided on what would bring closure to victims' families.
Whereas his wife, Dragana, told the BBC that Emwazi's death was "the last thing I would want for someone like him", Mr Haines' daughter, Bethany, told ITV News that she would only feel closure "once there's a bullet between his eyes".
Scrutiny is mounting over claims that Emwazi, a graduate from the University of Westminster, was already known to MI5 before he joined the ranks of IS in 2013.
But Mr Barfi, speaking to Sky News on behalf of the Sotloffs, rejected claims that British intelligence services had "dropped the ball".
He added: "The British have long been vigilant and have stopped a number of plans. This is not a replay of the Kouachi brothers, who were responsible for the Charlie Hebdo attacks.
"This is a completely different situation, and British intelligence has done as much as it could have, given the constraints of the democratic environment it works in."
Sir Menzies Campbell has said the Intelligence and Security Committee will likely seek answers about what information had been held on Emwazi - but this process will not take place until after the General Election.
According to Asim Qureshi, a director of the CAGE campaign group, Emwazi had been continually harassed by security agencies before he joined IS - and described the now-infamous militant as "extremely kind and gentle" and "the most beautiful young man".
Both Scotland Yard and Downing Street have refused to confirm reports of Emwazi's identity.
