German authorities confirmed on Tuesday that the 61-year-old man had left the prison after serving several years of his sentence.
“He is no longer in the institution,” Peter Brandeweide, head of the Lübeck prison said.
The formal refusal of early release was lifted by the Federal Court of Justice because an expert was sick and could not attend to testify to the danger the man poses.
The District Court in Kiel and the Higher Regional Court of Schleswig both refused to order the man jailed again because the public prosecutor had submitted the request at the wrong time.
Further attempts are underway to persuade the court to recognize the danger posed by the man so he can be jailed again.
Justice Minister Uwe Döring, who gave out details of the case on Tuesday said, “I very much regret that such a dangerous criminal has been freed on the basis of a formal irregularity.”
He said the man would remain under police surveillance, but said a round-the-clock observation would not be legally possible.