This is the Adelaide father who allegedly stabbed his three-year-old son.

An Adelaide father alleged to have fatally stabbed his three-year-old son has been formally charged with murder.

Landscaper David Janzow, 36, is understood to be facing a bedside court hearing this afternoon after undergoing surgery last night for a self-inflicted neck wound.

At a press conference yesterday afternoon, Superintendent Graeme Adcock said the investigation was still at an early stage and “we’re not able to say exactly whether it is mental health issues (that led to the tragedy)”.

“Understandably the boy’s mother is overcome by grief and police have not yet been able to take a statement from her,” he said.

“At this stage of the investigation there is no indication of any history of domestic violence.”

“Everyone is involved in this, as you can imagine — the mother and very close relatives and friends are extremely distraught, police officers involved are very upset and ambulance officers are very upset,” he said.

Friends and family gathered at the boy’s home to console his distraught mother.

Just days ago, Janzow uploaded a picture to his Facebook page of him and his two sons with the caption “unforgettable moments in a frog pond”. Other photos posted by his wife similarly show a happy family.

A neighbour of the family told News Limited that he was shocked and saddened by the news.

“I’m shaking, I mean for a child to die, I’m freaked out,” he said.

“They (South Australian Police) have spoken to me but they didn’t tell me what was going on.”

He also described Janzow as “such a nice guy” and he never suspected something like this could happen in their quiet suburban street.

Anyone who has information or who saw the ute en route to Athelstone is asked to contact police via Crime Stoppers on 1800 333 000 or on the website here .