Crown prosecutor Noel Sinclair says an all-female jury's acquittal of Wayne Silverfox shows the prosecution did not prove its case against the 51-year-old beyond a reasonable doubt.

The 12 Yukon Supreme Court jurors deliberated for six hours last week before returning with not guilty verdicts on all four charges.

The charges were: impaired driving, driving while under suspension, evading police and refusing to take a breathalyzer test.

Silverfox was arrested in Whitehorse last June 12 following a slow-speed chase. Also in the vehicle was Silverfox's 28-year-old son, Tyrell Sidney.

Silverfox has maintained he was not behind the wheel that day and that a man named Justin Charley, also known as Sam Frost, had been the driver.

Sinclair said in an interview the prosecution had to rely heavily upon the testimony of a single RCMP constable to reconstruct the events of June 12 for the jury.

Although Silverfox has about 70 prior convictions, said Sinclair, the jury was only made aware of 40 of them.

The jury was also not made aware of Silverfox's lifetime ban on driving.

However, the jury was presented with enough evidence to indicate that Silverfox 'was not an umblemished flower,' said Sinclair.

The Crown was concerned that a more complete background on Silverfox's criminal record may have led to 'propensity reasoning,' in which the jury would infer Silverfox's guilt based on past behaviour.

'It's not a safe way to make decisions,' said Sinclair.

'Obviously, (Silverfox) has a serious problem,' Louise Knox, western chapter service manager for MADD (Mothers Against Drunk Driving) Canada, said today from Edmonton.

'His record is an indication of his pattern (of behaviour). This has become his way of life.

'I wouldn't feel safe driving on the highways.'

Regarding the 12-woman jury, Sinclair said 'it was really a matter of chance because of the way the jurors are selected. (But) it's never happened in my experience. It certainly was unusual.'

Asked whether the unusual jury had an impact on the verdict, Sinclair said that would be 'the purest form of speculation. I don't think I could say one way or another.'

The decision will not be appealed, he added.