The UK only counts as murders or homicides those crimes which have a conviction . . . Additionally, the UK counts homicides as occurring when the trial is complete; a murder today may not be counted until 2016, and will be included in the 2016 statistics.
What a strange way of doing things. Collecting data in this manner systematically distorts the value of the statistics towards uselessness.
(1) Unsolved murders don't get counted at all
(2) There's no connection between when a murder occurred and when it is collected as data, because the criminal justice system does not have a predictable timetable from indictment to conviction. Two murders from sequential days could end up on different year tallies simply because of differences in the local courts' calendars. Which makes planning based on past data quite unreliable.
Do you have a cite explaining why this strange data collection method is still used? Aren't there coroner's verdicts or some-such?
Correction: Apparently the UK has trials (inquests, but in cases where they affect public safety, such as possible homicides, a jury is summoned? Or maybe it's passed on to the Crown Court? It's difficult to trace the laws down, but it does appear there is a substantial legal process) to determine cause of death in suspected homicides. So I misinterpreted the statements about the completion of trials there. See: http://www.legislation.gov.uk/ukpga/1988/13/contents
(US inquests -can- involve juries, varying by state, but rarely do.)
For the UK homicide y...
Of course, it turns out they're actually last among developed nations in real health outcomes.