Horse 1786 - The Year And A Day Rule On Homicide

In an old episode of New Tricks on Gem, DS Sandra Pullman mentioned to a chap that they were arresting on suspicion of murder that had he committed the murder just thirteen months earlier then he would have been absolved by the "Year and a Day Rule" which used to exist with respect to murder, manslaughter and aiding and abetting suicide.
I had heard of this rule before from a commercial law class oh so many years ago in relation to concepts like the Statute of Limitations, which then leads on to all sorts of juicy concepts of law like frustration and avoidance of contracts, but never having needed to study criminal law, it remained just an interesting aside. I just assumed that it still was a thing.

The Year And A Day Rule which used to exist was the common law presumption that a death was not a murder or manslaughter etc. if the death occurred more than a year and a day since the act which was alleged to have caused it, took place.

It is really hard to find examples of this existing in Australian law now, as the rule was abolished in New South Wales in 1990, Victoria, South Australia and Western Australia in 1991, in Queensland in 1992 and finally in Tasmania in 1993.
An idea of how the legislation used to read can be found in the New Zealand Crimes Act 1961, where it is still in operation:
http://www.legislation.govt.nz/act/public/1961/0043/latest/DLM329305.html
Death must be within a year and a day
(1)No one is criminally responsible for the killing of another unless the death takes place within a year and a day after the cause of death.
(2)The period of a year and a day shall be reckoned inclusive of the day on which the last unlawful act contributing to the cause of death took place.
- Section 162, Crimes Act 1961 (NZ)

The reasoning behind both the inclusion of the rule and its final aboliton can be found in the Hansard record which accompanies the The Law Reform (Year and a Day Rule) Act 1996:

http://www.parliament.the-stationery-office.co.uk/pa/ld199596/ldhansrd/vo960424/text/60424-08.htm
The Law Reform (Year and a Day Rule) Act 1996
The rule is a legacy of a time when medical science was so rudimentary that, if there was a substantial lapse of time between injury and death, it was unsafe to pronounce on the question of whether the defendant's conduct or some other event had caused the death. Medical science has now progressed to a point where it is possible accurately to link injury with death even if there is a significant time lapse. Moreover, advances in technology mean that seriously injured patients can be kept alive for long periods. This can have the effect, as in the case of Michael Gibson, of rendering impossible a prosecution for murder simply because of the year and a day rule. One can fully understand the additional distress that this must cause to a victim's family.
The Bill before us provides an opportunity to abolish this outdated rule and prevent such distress in future. 
- Law Reform (Year and a Day Rule) Bill, Lords Hansard Home Page, 24 Apr 1996

Basically it says that once upon a time, science was good enough to conclusively link acts which occurred more than twelve months before someone had died to that eventual death but now that forensic techniques have improved, that proof is now substantially good enough to be reliable.

It makes me wonder what the underlying meaning was in Edward Lear's poem "The Owl And The Pussy Cat"

Pussy said to the Owl, 'You elegant fowl!
    How charmingly sweet you sing!
O let us be married! too long we have tarried:
    But what shall we do for a ring?'
They sailed away, for a year and a day,
    To the land where the Bong-tree grows

- Edward Lear, The Owl And The Pussycat (1871)

They sailed away, for "a year and a day"? Why? Was this because The Owl And The Pussycat had performed some act which led to death and they didn't want to be charged with murder?

Maybe...