The inquests into the deaths of Michael Pedersen and his two children will be opened and adjourned tomorrow.
A post mortem examination has revealed that seven-year-old Ben and six-year-old Freya died from multiple stab wounds. Mr Pedersen, who was from Chertsey in Surrey, also died from stab wounds to the chest.
Their bodies were found in Hampshire on Sunday.
Police are not looking for anyone else in connection with the deaths.
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Metropolitan Police officer, Tom Harrison, has been crawling the course since the race began on Sunday morning.
The Old Bailey heard how Syed tried to get weapons online, including a bomb vest, and trawled the web to find a busy area launch an attack.
Hours after completing Sunday's course some of the runners put their medals on auction site eBay, with one attracting bids of almost £92.