Jason Alexander Downie pleaded guilty Wednesday before the Elizabeth Magistrates Court of killing 16-year-old Chantelle Rowe and her parents in their home in Kapunda, South Australia one year ago.

Downie, 18, appeared via videolink in the court packed with relatives and friends of the victims. He responded with "guilty" to the three counts of murder charges.

Downie was also charged with rape but this was withdrawn due to lack of evidence. The son of a Scottish immigrant will be sentenced next month.

The killing of the Rowes happened on Nov. 8, 2010. Only one family member, Christopher Rowe, survived. Downie was arrested nine days later.

Details of the murder are unknown. But the killer's identity has emerged.

Downie was working as a mechanic at a Barossa Valley car service centre for one year at the time of the killing. Co-workers described him as a skinny social outcast who did not fit with them, according to Adelaide Now.

On the day of the murder, he reported for work with large cuts on his arms. He told his co-workers that a bike crash caused the wounds.

The next day, when police announced the triple murder, Downie came to work but asked to go home saying the victim, Chantelle, was his best friend.

A TV station caught Downie attending the memorial for the victims on Nov. 13, 2010. He looked at the flowers and cards left the back of the victims' home.

On Nov. 16, the Kapunda police asked Downie's co-worker to bring him to the station for questioning.