After the fatal drive of a driver into a group of children in northern Hesse, the accused remained silent at the start of the trial.
He will not comment, he said on Monday before the Kassel district court.
The public prosecutor accuses the 31-year-old of intentionally driving into a group of seven and eight-year-old children in Witzenhausen (Werra-Meißner district).
Two girls were seriously injured and an eight-year-old was killed.
The victims' parents act as joint plaintiffs in the security proceedings.
It should be checked whether the man will be housed permanently in a psychiatric facility.
The public prosecutor accuses the Turkish citizen of, among other things, murder, attempted murder and dangerous bodily harm.
"He wanted to kill children," said the prosecutor when the indictment was read out.
First testimonies in court showed that there were warning signs before the crime: the 31-year-old was already known to the police for domestic violence and fraud investigations.
He was temporarily being treated for a mental illness, and he is said to have only reduced his medication or not taken it at all.
He also sent confused short messages to his brother the morning before the crime.
Investigators conclude from the angle at which the car was parked after the crime that he was deliberately approaching the children.
The 31-year-old himself said afterwards that his vision had gone black and that he didn't remember anything.
Three more hearings are scheduled for December.