Final figures for homicides in England and Wales for 2015 were released this week, numbers were up around 11% on 2014 from 517 to 573, but it's still one of the lowest rates in recent decades at 1.00/100,000 for England & Wales as a whole.
Also released were good for each local authorities, as these are small areas and the numbers of homicides in each one is often very low one guy going nuts and killing his wife and parents could send an area from the bottom of the list to the top for that year. So I've used an average for 2013, 2014 and 2015 to smooth out those odd events that might distort things.
City of London is way out at the top but it's an unusual area, only 8,000 people live there so 3 homicides in 3 years is enough to put it at the top of the list based on resident population, but on a typical weekday over 300,000 people work there.