The perpetrator is known to Germans as Tim K, which is the way all accused are referred to in the German media. I as a foreigner have somewhere (The Guardian?) picked up the boy's surname, though I won't mention it here.
Meanwhile the State Justice Minister in Baden-Wuerttemberg told the world at a press conference that the young man had had some psychotherapy involvement, according to his military call-up papers found in his room. Oh no, he didn't, say the parents. Oh yes, he did, says the director of the local psychiatric hospital - he was here five times, and then refused further treatment. Not sure about the role of the state minister, but I would have thought the hospital director's statement would be against all privacy legislation; it's not as if young Tim could have given his consent to this. Interesting.