German investigators are struggling to find the reason why a teenager with no evident problems shot 15 people dead before killing himself.
Three days after the bloodbath in the small southwestern town of Winnenden, near Stuttgart, Tim Kretschmer's personality remains elusive, as more contradictions surfaced.
Stuttgart prosecutor Siegfried Mahler, leading the inquiry, said on Thursday that the 17-year-old had been treated in a psychiatric clinic on several occasions between April and June.
He had then apparently broken off the treatments, Mr Mahler added.
But the lawyer for Kretschmer's parents, Achim Baechle, said the teenager had never attended such a clinic. His grandparents also said they knew nothing of this treatment.
Yesterday it emerged that a chilling Internet warning of his intentions attributed to Kretschmer by Heribert Rech, interior minister of Baden-Wuerttemberg state, was a hoax.
Dressed in black combat gear and armed with a gun taken from his father's bedroom, Kretschmer shot dead eight girls, one boy and three female teachers at his old school.
He then killed a passer-by outside a psychiatric clinic, allegedly where he had been due to receive treatment, hijacked a car and shot two others at a car dealership.
Pursued by armed commandos, he died in a shootout with police around 30km from the school. Police believe he shot himself.
Former classmates at the school described him as a boy who had friends, and a teacher at the commercial college where he studied later said he got on well with fellow students there.
The weekly Der Spiegel quoted investigators as saying that the evening before he went on the rampage Kretschmer spent two hours playing 'Far Cry 2', a video game in which players hunt arms traffickers in the jungle.
It said that an examination of Kretschmer's computer found that he regularly took part in Internet discussion forums, under the alias JawsPredator1.
He had referred to previous school massacres during his online exchanges, according to the magazine.
It quoted JawsPredator1 as writing in one forum: 'The funny thing is that even when they announced they were going to do it, no one believed them.'
But other sources said said that Kretschmer, who enjoyed playing table tennis but also frequented his father's gun club, was not a computer addict.
