Three dead bodies were found in a Bavarian hotel room on Saturday noon with crossbow bolts in their bodies.
The German police have opened an investigation in the death of three German citizens on Sunday.
Police have so far said that there are no indications that anyone else was involved.
The corpses were found in the remote riverside hotel in the city of Passau near the Austrian border.
The three were a 33-year-old woman and a 53-year-old man from Rhineland-Palatinate state and a 30-year-old woman from Lower Saxony, who had jointly booked the room on Friday.
Post-mortems will be carried out in coming days.