Two Russians became Britain's most wanted men after they were named as the prime suspects in the Novichok chemical weapons attack in Salisbury.
Astonishing CCTV images show Alexander Petrov and Ruslan Boshirov grinning as they walk around the Wiltshire city on the day former double agent Sergei Skripal and his daughter Yulia were poisoned with the military grade nerve agent.
The attack left a trail of the deadly chemical around Salisbury, with mother-of-three Dawn Sturgess dying after she came into contact with it and county police officer Nick Bailey being hospitalised during the investigation.
The CPS today announced Petrov and Boshirov are wanted for conspiracy to murder Mr Skripal and the attempted murder of his daughter. If caught, the Russian will also be charged with the attempted murder of DS Bailey and the use of Novichok contrary to the Chemical Weapons Act.
The pair were pictured leaving Britain at Heathrow Airport shortly after the attack and have never returned.
Prosecutors will not be applying to Russia for the extradition of the two men, as no agreement exists between the countries, but a European Arrest Warrant has been obtained.
Making the announcement, Scotland Yard's counter terror Commissioner Neil Basu said: 'Today marks the most significant moment so far in what has been one of the most complex and intensive investigations we have undertaken in Counter Terrorism policing; the charging of two suspects – both Russian nationals - in relation to the attack on Sergei and Yulia Skripal.'
Mr Basu said it is likely the suspects were travelling under aliases and Petrov and Boshirov are not their real names. They are believed to be aged around 40.
A CPS spokesman said: 'Prosecutors from the Counter Terrorism Division have considered the evidence and have concluded there is sufficient evidence to provide a realistic prospect of conviction and it is clearly in the public interest to charge Alexander Petrov and Ruslan Boshirov, who are Russian nationals.'
Russian authorities today denied knowledge of the two men, with foreign ministry spokeswoman Maria Zakharova telling reporters: 'The names published by the media, like their photographs, mean nothing to us.'
Former Russian double agent Sergei Skripal and his daughter Yulia were poisoned with the military-grade chemical weapon in the Wiltshire city in March.
Police officer Detective Sergeant Nick Bailey was also poisoned when he attended the retired spy's suburban home. Like the Skripals, he recovered after receiving life-saving treatment at the city's hospital.
In June, mother-of-three Dawn Sturgess died and her partner Charlie Rowley were hospitalised after they fell ill at his home in nearby Amesbury.
Police have now released an image of the perfume bottle used by the would-be assassins to transport the Novichok. Mrs Sturgess is said to found the bottle and put the substance on her wrists.
Today's announcement relates to the initial attack, but Mr Basu confirmed that officers have now linked the attack on the Skripals to events in Amesbury less than four months later, in which Dawn Sturgess, 44, and her partner Charlie Rowley, 48, were exposed to the same nerve agent.
Mr Basu said: 'We do not believe Dawn and Charlie were deliberately targeted, but became victims as a result of the recklessness in which such a toxic nerve agent was disposed of.
'We know that Novichok was applied to the Skripals' front door in an area that is accessible to the public, which also endangered the lives of members of the public and emergency service responders.'
Britain's most senior police officer, Metropolitan Police Commissioner Cressida Dick said: 'We remain absolutely determined to identify and bring about a prosecution in the UK courts of those persons responsible for these attacks and we will do all we can to get justice for the victims and their families.'
The Organisation for the Prohibition of Chemical Weapons (OPCW) confirmed yesterday the toxic chemical that killed Dawn Sturgess was the same nerve agent as that which poisoned the Skripals three months earlier.
The OPCW said it was not possible to conclude whether the nerve agent used in the two incidents was from the same batch.
Foreign Secretary Jeremy Hunt welcomed yesterday's report and again levelled the blame for the attacks at Russia.
He said: 'We are grateful to the OPCW for the independent expert work in confirming the type of nerve agent used in Amesbury, and once again pay tribute to the high standards set by our world-leading scientists.
'The recklessness of the Russian state in bringing a nerve agent into the UK, and total disregard for the safety of the public, is appalling and irresponsible. Our thoughts are with the family of Dawn Sturgess and with Charlie Rowley.'
In July, Assistant Commissioner of the Metropolitan Police Neil Basu said test results from Porton Down on the Amesbury poisoning had showed the victims to have been 'exposed to the nerve agent Novichok'.
The Russian state has denied involvement. Its embassy in London yesterday demanded access to the Skripals.
A statement released by the Russian Embassy on Tuesday claimed the circumstances of the March attack as 'obscure' and accused British authorities of keeping the Skripals in isolation ever since their release from hospital.
It said: 'They remain out of the public eye at an unknown location, unable to communicate freely with their relatives, friends, journalists or Russian officials, deprived of the freedom of movement.'
This article has been adapted from its original source.
© Associated Newspapers Ltd.