A 13-year-old boy is alleged to have killed a homeless man in the western German city of Dortmund, police and the public prosecutor's office said on Friday.
A mobile phone video shows how the child allegedly stabbed the man with a knife on Thursday evening.
The autopsy revealed that the 31-year-old victim had been killed by several stab wounds. It is certain that the fatal stabs were inflicted by a child "under the age of criminal responsibility."
There had been a verbal argument between the victim and the child beforehand. There were also corresponding statements from three other minors, who were also temporarily detained.
The police had provisionally detained four minors on Thursday evening. They were the 13-year-old, another child of the same age and two teenagers aged 14 and 15.
The two 13-year-olds, who were under the age of criminal responsibility, had already been released from police custody after their hearing.
A few hours after the offence, the victim was identified as a 31-year-old man who had no known place of residence.
Witnesses had observed an altercation and called the police. The four minors fled, but were provisionally detained minutes later.
According to the current state of the investigation, it can now be assumed that the four "met the victim by chance at the port," police reported on Friday.
Insults are said to have been exchanged between the 13-year-old and the homeless man. A scuffle ensued and the 13-year-old is said to have stabbed the victim. The alleged perpetrator is Bulgarian.
The knife thought to have ben used was tracked down by a police dog near the crime scene.
The 14 and 15-year-old were reportedly represented by a lawyer and were also released on Friday. "It is currently unlikely that they were involved in the child's offence."