John Yates is viewed as being "very able" in many fields of policing
Assistant Commissioner John Yates is to take over as head of counter-terrorism at the Metropolitan Police, after his colleague Bob Quick resigned following a security blunder.
Despite his 28 years of service at the Met, the new job will undoubtedly present the experienced officer with a "steep learning curve", says BBC security correspondent Frank Gardner.
He has been thrust into the job without warning, after Mr Quick's error - being photographed revealing the contents of a secret document as he arrived at Downing Street - caused a major anti-terrorism operation to be brought forward.
Before the move Mr Yates had a wide portfolio at the Met - including police complaints, intelligence, legal matters and specific high profile police investigations.
His previous experience ranges from senior involvement in investigating police corruption, to probing the "cash-for-honours" row, to leading the UK policing response to the Asian tsunami on Boxing Day 2004.
His CV also includes knowledge of investigating rape, street crime, organised criminal networks and gun crime.
But it doesn't involve counter-terrorism.
"It's a huge mantle to take on and those under him will have to brief him very quickly now," says our correspondent.
'First class job'
Mr Yates, unlike Bob Quick, does not have a "pedigree" in this field. While he is viewed as "very able" in many areas, "counter-terrorism is a special area where people have come to it either from Special Branch or what used to be the anti-terrorism branch".
"He's going to have to go on a relatively steep learning curve," said Mr Gardner.
But he is not short on votes of confidence.
Responding to the appointment Sir Ken Jones, president of the Association of Chief Police Officers (Acpo), said Mr Yates had "extensive investigative experience from many years in frontline policing".
Meanwhile, London Mayor Boris Johnson said Mr Yates would do a "first-class job" and the deputy chair of the Metropolitan Police Authority (MPA), Kit Malthouse, said his involvement in so many high profile investigations had equipped him well for the position.
Mr Yates joined the Metropolitan Police in 1981, spending time both in uniform and as a detective.
He went on to lead investigations into more than 20 murders.
The senior policeman worked as staff officer to Met Commissioner Paul Condon during the period of the Macpherson Inquiry into the death of black teenager Stephen Lawrence between 1999 and 2000.
In the same years Mr Yates' reputation was further cemented when, as a detective superintendent, he led a massive internal police corruption inquiry into 9 Regional Crime Squad, based in East Dulwich.
It ended with six serving narcotics detectives being jailed for a drugs conspiracy.
The case involved the first female "supergrass", a drug dealer, who became the lover of the group's ringleader. After the investigation began another officer, Detective Constable Neil Putnam, turned informer and gave evidence that was the mainstay of the prosecution's case.
Mr Yates further established his reputation as a robust operator capable of handling cases in the media spotlight with his involvement in the perjury case of Lord Archer, as well as the failed prosecution of royal butler Paul Burrell and the Who Wants to be a Millionaire fraud trial.
Following the Boxing Day tsunami he headed Operation Bracknell, which opened a bureau to log details of those missing, describing it as an "unprecedented challenge".
Almost 2,600 police officers from across the UK were deployed to help.
Mr Yates' achievements during the tsunami response led to him being awarded the Queen's Police Medal (QPM).
He also went on to lead the Met's response to the shooting of Jean Charles de Menezes at Stockwell Tube station, in the wake of the July 2005 London bombings.
Mr Yates said he was "humbled" by the dignity shown by Mr Menezes' parents after he met them in their Brazilian home town of Gonzaga that year.
The 2006 inquiry into whether peerages were offered in return for party donations was one of his toughest and most sensitive challenges.
The police investigation, during which more than 130 people were interviewed and four people were arrested, focused on allegations that peerages had been offered in return for loans to Labour and the Conservatives ahead of the 2005 general election.
The investigation included the arrest of Lord Levy, Labour's chief fundraiser and one of the then prime minister Tony Blair's closest allies.
Figures questioned by officers included Mr Blair and former Tory leader Michael Howard.
No charges were brought following the 16-month police inquiry.
Defending the inquiry, Mr Yates said he had received "less than full co-operation" from some people involved.