An ambush defence is one in which defence evidence - notably from expert witness

Expert witness

An expert witness, professional witness or judicial expert is a witness, who by virtue of education, training, skill, or experience, is believed to have expertise and specialised knowledge in a particular subject beyond that of the average person, sufficient that others may officially and legally...

es - has not been adduced in advance to the prosecuting authorities, leading to their inability to rebut it. The term is used in United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 jurisprudence. Since 1987, the possibility of the ambush defence has been much reduced by The Crown Court (Advance Notice of Expert Evidence) Rules 1987, made under section 81 of the Police and Criminal Evidence Act 1984

Police and Criminal Evidence Act 1984

The Police and Criminal Evidence Act 1984 is an Act of Parliament which instituted a legislative framework for the powers of police officers in England and Wales to combat crime, as well as providing codes of practice for the exercise of those powers. Part VI of PACE required the Home Secretary...

, which in essence require the defence to provide the prosecution with copies of expert witness reports in sufficient time for the prosecution to consider the nature of and if necessary prepare rebuttal evidence opposing the report.

An example of the ambush defence is found in a paper given by Judge John Milford QC

John Milford

John Milford was an American actor in theatre, television, and films, playing scores of roles, often as a western villain....

 at a 1994 Joint Conference entitled "Beyond reasonable doubt" organised by the Royal Society of Medicine

Royal Society of Medicine

The Royal Society of Medicine is a British charitable organisation whose main purpose is as a provider of medical education, running over 350 meetings and conferences each year.- History and overview :...

 and the Expert Witness Institute. Discussing the trial of a train driver following the 1984 derailment of a train near Morpeth

Morpeth, Northumberland

Morpeth is the county town of Northumberland, England. It is situated on the River Wansbeck which flows east through the town. The town is from the A1, which bypasses it. Since 1981, it has been the administrative centre of the County of Northumberland. In the 2001 census the town had a population...

 he wrote:

The case of R v Allen 1985 illustrates the position which applied hitherto. The driver of a train which came off the rails at the Morpeth curve was prosecuted for driving under the influence of alcohol. However, the defence at the last minute provided medical evidence which suggested that at certain times the driver might pass out and the prosecution not having prior knowledge of this were unable to rebut it. The driver was acquitted.

External links

• Court Management of Expert Witnesses article in the Expert Witness Institute newsletter, Autumn/Winter 2004, from which the above excerpt is taken.