LONDON, Sept 21 (Reuters) - British police on Tuesday said a third Russian man was involved in the nerve agent attack on double agent Sergei Skripal in southern England three years ago. Police said there was evidence to charge the man, Denis Sergeev, who went by the alias Sergei Fedotov, with plotting to kill Skripal and the attempted murder of his daughter Yulia and a police officer who was also exposed to the Novichok. Here are British police"s details about the attack: - "Sergei Fedotov" flies to London"s Heathrow airport from Moscow on Friday, March 2, 2018, four hours before two other Russians, travelling under the names Ruslan Boshirov and Alexander Petrov, arrive at London"s Gatwick airport from the Russian capital. - Petrov and Boshirov spend two nights in an east London hotel, where traces of the Novichok nerve agent were found. They make day trips to Salisbury, the first for reconnaissance and the second to attempt to kill Skripal. - British police say Fedotov, Petrov and Boshirov are members of a Russian military intelligence (GRU) unit tasked with special operations abroad such as the attempted murder of Skripal. - Fedotov stayed at a separate London hotel and remained in London over the weekend. No nerve agent was detected in his hotel. However, he met the other two suspects on several occasions. - Petrov and Boshirov are caught on security cameras near Skripal"s house in the city of Salisbury. Police believe they sprayed the Novichok nerve agent on the door of the former Russian GRU officer"s house. - Skripal, who betrayed dozens of agents to Britain’s MI6 foreign spy service, was found unconscious with Yulia on a public bench in Salisbury on March 4. - Fedotov flew out from Heathrow on March 4, hours before the other two also left Britain. - In July, local woman Dawn Sturgess, a 44-year-old mother of three, died and her partner Charlie Rowley also fell ill after he found a fake bottle of Nina Ricci perfume which police said had been adapted to administer the nerve agent. Charges have yet to be filed in Sturgess"s death, and police say they are still investigating how the poison reached Rowley. - In September 2018, British police charge Boshirov and Petrov over the attack on Skripal. - A week later Boshirov and Petrov appear on Russian TV to say they were tourists who had travelled to Salisbury to do some sightseeing. "There"s the famous Salisbury Cathedral. It"s famous not only in Europe, but in the whole world. It"s famous for its 123 metre-spire," Boshirov said. - In April 2021, the Czech authorities said they were searching for Boshirov and Petrov in connection with an ammunition depot explosion in 2014 which killed two people, an attack which had been aimed at a shipment to a Bulgarian arms dealer. read more - On Tuesday, British police say charges have also been brought against Fedotov. They say his real name is Denis Sergeev and that Alexander Mishkin and Anatoliy Chepiga are the true identities of Boshirov and Petrov. - Police are also investigating a number of other people who might have been involved. Dean Haydon, the UK"s Senior National Coordinator for Counter Terrorism Policing gave no details about who they were looking at, bar saying there were no female suspects.