Horror Sydney crash: Alleged drunk driver who killed four kids to plead guilty

Siblings Sienna, Angelina and Antony Abdallah, who died on February 1. Photo / 7 News

A driver who was allegedly drunk and high on drugs when he ploughed into and killed four children on a quiet Sydney street this year will plead guilty to four counts of manslaughter, a court has heard.

Samuel William Davidson had allegedly been drinking since the early morning on February 1 before he got behind the wheel to drive to a service station in Oatlands, in the city's north-west.

About 7.45pm, while allegedly travelling at more than double the speed limit, the four-wheel-drive he was driving left Bettington Rd and careered into a group of seven kids who had set off to buy ice cream.

Four of those children – siblings Antony, 13, Angelina, 12 and Sienna Abdallah, 9, and their cousin Veronique Sakr, 11 – were killed.

On Thursday, the clean-shaven Davidson told Parramatta Local Court he would plead guilty to several charges at his next court date.

"Yes, your Magistrate," he replied when asked to confirm what his lawyer had revealed to the court.

Those charges include four counts of manslaughter, two counts of causing grievous bodily harm by misconduct in charge of a motor vehicle and one of aggravated dangerous driving occasioning grievous bodily harm while under the influence of drugs.

Court documents allege the 30-year-old was found to have MDMA in his system following the crash. He was also allegedly three-times over the blood alcohol limit, blowing 0.15.

He will return to court on October 22 where he is expected to be committed for sentence.

Davidson, the son of a retired police officer, had been facing 34 charges in total.

The court heard the balance of those charges would be withdrawn upon entering guilty pleas to the seven charges indicated on Thursday.

Members of the Abdallah and Sakr families were not present, and have previously spoken about their decision to avoid Davidson's court dates and instead "trust in the Australian judicial system".

"We're determined to spend time with our children who are still with us and remain in constant prayer for the strength we need to see us through this time," Daniel Abdallah, the father of the Abdallah children, said in a statement.