Who killed Dian Fossey?

About the book:
In this Africa - novel the autor mixed facts of the unexplained murder of Dian Fossey with another fictional criminal case with reference to the painful history of Rwanda and Congo . At the end of the hunt for a murderer, the mysterious murder of the gorilla researcher appears in a new light.

Twenty years after the murder of Dian Fossey, a horribly mutilated male corpse is found on the shores of Lake Kivu in Rwanda. Chief Inspector Jean Bosco Kabeera and his team, including the visiting German criminal investigator from the Federal Criminal Police Office (BKA), Ariane Manstein, face intense pressure to solve the murder. First, it stands to reason the crime is connected to the trade of rare earth, a thriving business in the border region around Goma/Gisenyi. Nevertheless, it is possible it was a ritual murder. The dead man's face was covered with a wooden mask. But, while their investigation bore noticeable strange similarities to Dian Fossey's murder in 1985, it is rather difficult to connect it to their current case. The investigation eventually leads them to the eastern part of the Congo where the investigators encounter extreme danger. The investigation continues with the help of the Goma headquarters commander Joseph Likongo until Kabeera and his team identify the main perpetrator ultimately responsible for the murder of Dian Fossey as well as for other crimes committed in eastern Congo. Bosco Kabeera has to convince the prosecutor general to let him look at Dian Fossey's case file because only her notes, which had been classified top secret, can provide final proof.