German police have revealed new details about the 15-year-old attacker who killed the 17-year-old Ukrainian basketball player Volodymyr Yermakov, and non-fatally wounded another Ukrainian who is now hospitalised in critical condition.

As reported by Bild, according to the police officer, the attacker stabbed the two Ukrainians at least nine times in the chest and stomach. 

"He obviously acted with a depraved indifference to human life. And there were no signs of remorse when he was arrested. Apparently, he had been desensitised by many [previous] criminal offences and clashes with the police," the police spokesman said.

In addition to two Ukrainians, a 15-year-old German of Turkish origin also attacked a 13-year-old girl from Lebanon and a 14-year-old schoolboy from Syria, who were trying to help after witnessing the two basketball players being stabbed.

"They were injured in their arms and hands. These are serious injuries, but fortunately not life-threatening ones. One of them has already been released from the hospital," the investigator said. 

Law enforcement officers stressed that before the attack on Ukrainian basketball players, the 15-year-old teenager had committed numerous other crimes and had a record with the North Rhine-Westphalia police. 

The district judge issued an arrest warrant for the young man for negligent homicide and grievous bodily harm. Another 14-year-old boy, who took part in the attack but did not directly stab any victims, was also arrested.

"This is an incomprehensible act with no clear motive. The attacker deliberately sought a confrontation with older, taller and more athletic Ukrainians and then immediately and ruthlessly used a knife," the officer added. 

According to law enforcement officers, on the evening of 10 February, a violent argument broke out between two groups of young people at a bus stop on Willy Brandt Square in Oberhausen.

At first, they argued on the bus, but the conflict ended in a physical fight after they got off the bus in the aforementioned square.

As a result of the incident, four young people were seriously injured, presumably by knives. The attackers fled the scene of the crime. 

Soon, the 17-year-old Ukrainian died of his injuries in hospital, despite the operation. 

The next day, law enforcement officers detained two suspects: a 15-year-old boy from Gelsenkirchen and a 14-year-old from Herne. Both were previously known to the police. 

The Basketball Federation of Ukraine reported on the death of 17-year-old Ukrainian basketball player Volodymyr Yermakov in Germany; the Kyiv City Basketball Federation (FBK) adds that the young man died as a result of the attack.

Later, the Ministry of Foreign Affairs of Ukraine reported that the German police detained the killer.