Public prosecutor Rüdiger Ihl told the paper that a 20-page file of charges had been sent to the district court in the city of Wuppertal in North Rhine-Westphalia, near to the town of Velbert, where the attack happened.
“The appropriate panel will decide on the opening of proceedings and the trial date,'' he said.
The boy allegedly beat Kassandra nearly to death with a rock before dragging her into a covered drainage ditch through a heavy manhole cover and dumping her 1.5 metres below ground.
She was found by a search dog after lying in the ditch for hours.
Bild reported the boy, who attended a special school for adolescents with emotional problems, would face a closed court in spring. He had so far denied wrongdoing, the paper said.
However, witnesses saw him with Kassandra around the time of the assault on September 14, and investigators found fibres from the girl's clothes on him.
The boy came to the attention of the investigators not long after Kassandra was found in critical condition though with no signs of sexual abuse. The day before the attack she had attended a Catholic youth group meeting but did not return home, prompting a call to the police from her worried parents.