A driver who fell asleep at the wheel causing the death of a young mother and seriously injuring her baby has been freed from jail.

The Court of Appeal ruled the two-year sentence imposed on Anthony Handley was unduly harsh.

The 64-year-old from Whitethorn Grove, Artane, Dublin, had pleaded guilty at Dublin Circuit Criminal Court to dangerous driving causing the death of Olivia Dunne and serious bodily harm to Éabha Dunne after a crash in Balbriggan on 17 January 2014.

The court heard the 31-year-old mother was killed instantly when she was hit by Handley's car as she walked along a footpath with her then three-month-old baby.

Witnesses said the car had crossed onto the wrong side of the road "without warning, like a rocket" and had struck Ms Dunne and the pram from behind.

The court was told that garda crash experts had concluded driver fatigue was the most likely cause of the crash.

An expert report presented to the court last year described what is known as a "micro sleep", where drivers can be asleep with their eyes open for up to ten seconds.

Handley had had four hours sleep the night before, but he said for him that was a normal night's rest.

At the sentence hearing last year his lawyers had asked the court to consider a suspended sentence saying his sudden onset of sleep could not have been forseeable.

They said unlike other cases, there were no aggravating factors such as speed or alcohol.

But Judge Pat McCartan said while he was a caring and decent man with a clean record, he should have been aware he was becoming tired behind the wheel and done something about it.

The judge said he needed to send out a message and sentenced Handley to two years in jail in May last year and banned him from driving for ten years.

Today the Court of Appeal ruled that sentence was unduly harsh.

The three-judge court found there were errors of principle in the sentencing of Handley.

It ruled the sentencing judge unfairly penalised him for a delay in pleading guilty.

The court said Judge McCartan had "erroneously attributed to him a motivation to explore a technical or other defence and deemed his efforts to investigate the medical cause for the accident as in some way diminishing the extent of his remorse."

The court said it was not the case that he had embarked on a fishing exercise in the hope of identifying a medical cause for losing consciousness while knowing the true cause was that he had fallen asleep at the wheel.

The appeal court said the sentencing judge attached insufficient weight to the totality of mitigating factors and particularly Handley's role as his wife's main carer.

The judges said the net custodial sentence was "unduly harsh"

The court also said in arriving at these conclusions it was anxious to emphasise that "by any standard this accident was a dreadful tragedy with the most appalling consequences for the family of Mrs Dunne and her young daughter Éabha."

The court said it would allow the appeal and would re-sentence him to two years in jail but suspend the unserved portion of the sentence.

Handley's family broke down in tears in the court as he was released from custody and left court having served nine months in jail.

The court upheld the ten year driving ban and noted that in itself was a severe penalty for a man of his age.