The majority of the 100 extra officers will be of constable rank, and the unit will lose Det Ch Supt Duthie, who will become head of homicide next month, and one superintendent.
He stressed that officers will retain their specialisms in terms of the types of crime they investigate.
"This is a high-risk area and we need to make sure that we've got the right people with the right training."There would be a danger if we were to use 'omnicompetent' officers. But we've made a conscious decision that this is a high-risk area, we need to have dedicated officers investigating dedicated types of crime."
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The plaque at number 16 Cowley Street in Westminster marks the brown brick Georgian townhouse where Sir John lived for 31 years.
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Metropolitan Police officer, Tom Harrison, has been crawling the course since the race began on Sunday morning.