A SCHOOLBOY "loner" who killed his sister as part of a plot to murder his family is facing life behind bars.

The 16-year-old goth dressed as a character from hit film The Matrix before setting fire to his home in Brockley, leaving his sister to choke to death.

The fire was part of the boy's elaborate plot to kill off his family so he could be adopted by wealthier parents.

The Old Bailey heard how the boy, who cannot be named for legal reasons, mapped out his scheme on pages ripped out of a school exercise book.

Under the heading Operation New Life, he wrote "Kill family, lose memory, get adopted by a rich couple it all starts".

The boy, who was 14 at the time, claimed the plot was dictated to him by an identical twin called Dante, who followed him around and gave him advice.

The court heard how the boy developed an obsession with violent video games.

He also spent most of his spare time painting figurines from the Warhammer board game, which he used to map out his evil plan.

On the night of the fire, April 24, 2004, the boy battered his brother over the head with a shovel.

He then dressed in a long trench coat, black jeans and black boots like Keanu Reeves in his favourite film The Matrix and torched his home.

The boy's parents, eldest sister and 12-year-old brother escaped the burning house but his asthmatic sister died of smoke inhalation.

In a statement the boy's mother admitted her son was "a bit of a loner".

She added: "Out of all of the children he was the one I knew the least.

"He was secretive and private. He would write stories. I knew they involved shooting and drama."

An Old Bailey jury decided the boy was guilty of murdering his sister, attempting to murder his brother and arson with intent to endanger the life of his family.

He will be sentenced once psychiatric reports are prepared.