Colin Duffy trial: Voice analyst 'did not adopt former boss's report'

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Colin Duffy appearing outside court in 2017Image source, PAcemaker
Image caption,
Colin Duffy, 52, is on trial in relation to an attack on a police convoy in December 2013 - pictured here outside court in 2017

A forensic voice analysts who examined recordings of three men allegedly discussing a murder bid has rejected suggestions she adopted her former boss's report to back up his findings.

Dr Christin Kirchhurubel analysed the recordings after Prof Peter French.

They both concluded there was moderate to strong support the recordings were of the three defendants.

Colin Duffy, Henry Fitzsimons and Alex McCrory deny preparing and directing terrorism, and membership of the IRA.

Mr Fitzsimons and Mr McCrory also deny attempting to murder police officers on 5 December 2013.

The men are also charged with possessing two AK47 assault rifles and ammunition used in the attack.

The three men were allegedly covertly recorded and videoed in an MI5 operation in Lurgan the day after a gun attack on a police convoy on north Belfast in which two gunmen fired 14 shots at three PSNI vehicles.

Original analysis of the recordings was carried out by Prof French and his Forensic Speech Laboratory, before Dr Kirchhurubel also studied them.

She was working for him at the time, but is now in private practice.

She rejected suggestion from the defence that she would have simply adopted Prof French's findings.

At one stage she told the Diplock-style non-jury trial she would not have allowed her duty to Prof French to outweigh her duty to the court.

The judge told her that while her "good faith" was not in question, the court had to consider the degree of risk of bias involved in her report reaching the same conclusions as Prof French.

Dr Kirchhurubel accepted that forensic experts were always open to cognitive bias, but that they could deal with the possibility simply by being aware of it.

The defence also put it to her that the analysis was open to "bias" from the outset as the police transcript of materials contained the names of the accused and the police belief they were the men in the MI5 recordings.

A defence barrister said this would have presented a higher risk of cognitive bias in the case, since "the bias is there from the very start...that these three people feature in these conversations".

Dr Kirchhurubel said while experts had to be alive to the potential risk, and being aware of cognitive basis, such bias could be limited by making amends to mitigate it.

The defence barrister suggested that given the "knowledge was other words the damage was done', and as such, "the bias is inherent in that police have made up their own mind".

Dr Kirchhurubel agreed: "The knowledge was there. Yes."

She added later it would have been better if no background information had been included in the police instructions.

However, Dr Kirchhurubel said as an expert she was not interested in whether or not the recorded voices were those of the defendants, as named by the police, nor had she any interest in the eventual outcome of the trial in itself.

The trial continues.