“That was a mistake,” said police spokesman Gerhard Stelke.
German authorities checking the manifest of the MCS Poseia cruise ship coming from Norway to Kiel, found his name on the list, and moved in on Saturday to arrest him.
The 65-year-old had deliberately not left the ship in Kiel, thinking that because it had a foreign flag, he was on foreign territory.
He received a quick international law lesson when the German police took him away, explaining that they did in fact have jurisdiction.
The man, an Austrian, was convicted 13 years ago in Essen of murder, robbery and breaking gun laws, and sentenced to life in prison. How he escaped was not revealed on Monday – but authorities took him to Kiel jail.