Frognerbadet is the site associated with Marit Olsen’s hanging and the forensic clue that connects her murder to an old rope factory. A magnified image of the rope’s cut surface from Frognerbadet provides the reference for a match that shows the murder weapon came from a specific spool and had been cut there recently.

Place in the Investigation

The investigation identifies Marit Olsen as having been hanged at a diving tower with rope from an old rope factory. Frognerbadet enters the forensic inquiry through a stored laboratory image of the rope’s cut surface: Björn Holm compares it with the end of a rope at the factory, using a 25-times magnification of the Frognerbadet sample.

The Rope Connection

The comparison establishes a precise match between the cut surfaces. The rope used to hang Marit Olsen had not merely come from the same rope factory as the spool under examination; it had been cut from that very spool. The cut was fresh, indicating that the person who took the rope had been at the factory not long before the investigators arrived.

Significance

Frognerbadet functions as one end of a physical trail: the murder scene yields a trace that can be matched to a particular spool elsewhere. The finding narrows the question from the rope’s general origin to who could have taken it from the factory, and Kaja Solness reasons that whoever obtained it must know the area and is unlikely to be separated from the killer by many intermediaries. In this way, the location’s importance lies not in a broader description of the baths but in the evidence that carries the investigation from Marit Olsen’s death toward the rope’s recent source.