Is there legal precedent for that?? I know there is for sleep walking etc.
'Automatism' - it wasn't me, I had no control' -
The recent New South Wales Court of Criminal Appeal decision of Woodbridge v R [2010] NSWCCA 185 is an example of the courts approach to the defence of automatism.
The appellant was intoxicated when she drove into an oncoming car, killing the female passenger and severely injuring the driver.
The defence case was based on the fact that the appellant's driving on the day of the accident was not a voluntary or willed act and put forth a defence of "sane automatism".
The arguments put forth highlighted that phone calls from the appelant's ex-husband caused her to go into a dissociative state and therefore rendering her behaviour involuntary on the day of the collision.
The trial Judge did not allow the issue of sane automatism to go to the jury. This issue was argued on appeal.
The distinction between "sane automatism" and "insane automatism" is important and was highlighted in R v Radford (1985) 42 SARS 266 at 276:
· Insane automatism refers to the reaction of an unsound mind to its own delusions or to external stimuli.
· Sane automatism refers to the reaction of a sound mind to external stimuli including stress-producing factors.
It was decided on appeal that the psychologists identified that the phone calls from the ex-husband as the main trigger for the automatism suggests that the appellant's mind was unsound rather than sound. The nature of the phone calls received from the husband were not so extraordinary and extreme to assume that a completely healthy mind would have been so affected as to react in the way in which the appellant did.
http://criminallawcentre.com.au/Defence_of_Automatism
I think he might be going for this -'diminished responsibility'
Diminished responsibility is one of three special defences which exist solely for the offence of murder. It is contained in the Homicide Act 1957 as modified by the Coroners and Justice Act 2009. Where the defence of diminished responsibility is successfully pleaded, it has the effect of reducing a murder conviction to manslaughter. The three special defences of diminished responsibility, loss of control and suicide pact differ from general defences in that they do not apply to all crimes and also the effect is to reduce criminal liability rather than to absolve the defendant from liability completely.
Diminished responsibility is set out in s.2 of the Homicide Act 1957 as ammended by s.52 of the Coroners and Justice Act 2009. To rely on the defence, the defendant must be able to demonstrate the following:
1.An abnormality of mental functioning caused by a recognised medical condition.
2.Which provides an explanation for the defendant’s acts or omissions in being party to the killing.
3.Which substantially impaired his/her mental ability to either:
a) Understand the nature of their conduct or
b) Form a rational judgment or
c) Exercise self–control
1. Abnormality of the mental functioning caused by a recognised mental condition.
The question of whether the defendant is suffering from an abnormality of the mental functioning is for the jury to decide after hearing medical evidence. The jury are not bound to follow medical opinion it is ultimately their decision as to whether the defence should succeed. A notorious example of the jury ignoring medical opinion was present in the trial of Peter Sutcliffe (the Yorkshire ripper) where the medical opinion was unanimous that the defendant was a paranoid schizophrenic, yet the jury refused to allow him the defence. Abnormality of the mental functioning is assessed by reference to what a reasonable man would regard as abnormal. It has a wide meaning and encompasses the inability to exercise will power and control.
2. The abnormality must provide an explanation for D’s act or omission in being party to the killing.
3.Which substantially impaired his/her mental ability
The defendant must show that the abnormality of the mind must have substantially impaired his mental ability to either:
•Understand the nature of their conduct or
•Form a rational judgment or
•To exercise self –control
http://www.e-lawresources.co.uk/Diminished-responsibility.php
ETA: either of the above +/- 'disassociative amnesia'