Marcin Zdun trial: The four things the jury will consider

Marcin Zdun, 40, faces two counts of murder following the death of his wife Aneta, 40, and daughter Nikoleta, 18, at their home in Wessex Road, Salisbury on June 1.

On Wednesday (December 2), Zdun appeared before a jury having previously pleaded not guilty to both charges.

In his opening statement, prosecutor Nicholas Haggan QC said the former Tesco worker doesn't deny killing his wife and daughter but claims he has "no recollection of what he did that afternoon".

"Whether that assertion is true or whether the defendant finds it convenient to say that he cannot remember what happened will be an issue for you to consider in the trial," Mr Haggan said.

Addressing the jury, Mr Haggan laid out the four questions jurors will need to consider before deciding whether Zdun is guilty of murder or manslaughter.

These are:

1. Was the defendant suffering from an abnormality of mental functioning?
2. Did the abnormality of mental functioning arise from a recognised medical condition?
3. Did the abnormality of mental functioning substantially impair the defendant's ability a) to understand the nature of his conduct and/or b) to form a rational judgement and/or c) to exercise self-control?
4. Did the abnormality of mental functioning cause or was it a significant contributory factor in causing the defendant to kill Aneta and/or Nikoleta?

"This defence is known as diminished responsibility," Mr Haggan said.

During the trial, the prosecution will argue that Zdun killed his wife and daughter not because he was suffering from an abnormality of mental function "but because he was jealous and angry not only about Aneta's perceived affair but also the loss of his controlling influence over his wife and daughter".

The court heard yesterday that Zdun wrongly believed his wife was having an affair with another Tesco worker.

He also "did not like the closeness of the relationship between Aneta and Nikoleta".

The trial continues.