At approximately 12.51 pm on Friday, 18 April 2008, the offender was driving his red Commodore registration number 1COI-532, in a westerly direction along Berehaven Avenue, Thornlie. The offender was speeding. In that area, Berehaven Avenue is a single carriageway sealed road in a good state of repair that runs predominantly in a south-west, north-eastern direction. There is no line marking the centre of the road.
Berehaven Avenue is in a residential area, and the speed limit is 50 kilometres per hour. The day was overcast, but visibility was good and the road was dry. Ahead of the offender, travelling in the same direction, were two vehicles. The first of the two vehicles, a yellow Hyundai Elantra, had slowed down with the driver signalling her intention to turn right into Pryor Street.
As he approached the two vehicles, the offender accelerated heavily and moved onto the incorrect side of the road to overtake the two vehicles in front of him. The driver of the yellow Hyundai had started to turn right into Pryor Street. The front left side of the offender's Commodore collided heavily with the front right of the Hyundai.
The offender's vehicle then speared off towards the north-[w]est corner of the intersection. The Commodore then mounted the curb, became airborne, and travelled over the front yard and garden bed of the house situated at 145 Berehaven Avenue. The Commodore landed on the grass between a garden bed and driveway of that house and continued in a north-westerly direction.
At that time, Mrs Tania Moorby, who resided at 145 Berehaven Avenue with her husband Jamie Moorby and their 11-month-old daughter, Grace, was just returning from the shops on foot with Grace secured in her pram by a harness. Following a brief stop at the letterbox to collect the mail, Mrs Moorby began pushing the pram up the driveway towards the house, when she and the pram containing Grace were hit by the Commodore driven by the offender.
The Commodore then went through the brick wall separating 145 Berehaven from 147 Berehaven Avenue, which showered debris across the front garden and onto the roof of the house at 147 Berehaven Avenue. The Commodore then collided with the front porch area of that house, causing extensive structural damage.
As a result of the collision, Mrs Moorby was thrown into the air and she came to rest in the front garden of 147 Berehaven Avenue. She sustained broken ribs and abrasions. Gracy Moorby came to rest in the front porch area of 147 Berehaven Avenue. Grace sustained severe injuries, including head injuries, and died at the scene.
Several minutes after the collision, the offender left the scene on foot. He was pursued by members of the public. Some of them caught up with the offender about 400 metres away in Elvington Way. One man was talking to the offender and had persuaded him to return to the scene when a police officer arrived.
The offender was taken to Cannington Police Station where a breath analysis test was administered. The test gave a reading of 0.181 grams of alcohol per 210 litres of breath, which was calculated to have been 0.166 grams of alcohol per 210 litres of breath at the time of the collision. When given the breath test, the offender said that he had had his last drink containing alcohol early that morning, probably at 2 or 3 am.