A lawyer defending a man accused of complicity in a 2009 armed robbery attacked the prosecution's main witness during a trial by jury today, saying his record of 10 convictions contrasted with his client's, which was "impeccable".

Lawyer Michael Sciriha said he had chosen to defend Matthew Mizzi, 29,  because he genuinely believed he was innocent.

On the other hand, Jonathan Coleiro, who is serving 15 years for his involvement in the hold-up, was the mastermind of the crime, which he had designed and carried out on his own.

Mr Mizzi, from Cospicua, stands charged with complicity in the armed robbery in April 2009 during which the shop keeper was shot twice.

Dr Sciriha said his client's misfortune was his timid nature and his below average IQ that made him vulnerable. He said Mr Mizzi's criminal record was spotless, as opposed to that of Mr Coleiro. Jurors should be wary of the "hidden interests" of those who chose to testify.

Referring to Mr Coleiro's testimony, Dr Sciriha said jurors could see how arrogant he was, arguing with those asking questions and even contradicting other witnesses, including the police inspectors who had investigated the case.

He said it was Mr Coleiro who chose the target and who procured the weapon, something for which he was now trying to shift blame onto Mr Mizzi.

Dr Sciriha also expressed dissatisfaction with the police investigation, especially the fact that no fingerprints were taken from the weapon used.

The trial continues.