Loukko by 
An old woman is found hanged in a forest. Paula finds out that she had terminal cancer and had almost emptied her apartment, knowing to die soon. Her death is considered a suicide, but Paula is not satisfied with it. There is something wrong in the picture.
A famous mountain climber is found hanging above a seesaw in a playground. On the other end of the seesaw Paula finds sand that is far too fine to be natural – the same kind of sand that was found at the forest. Paula realizes that the victims have been forced to balance on a seesaw before death, fighting for their lives. Paula Pihlaja has barely started the investigation when a third body turns up – a teenage boy, at another playground, hanged. A serial killer is on the loose.
Third title in the series, Logboat (Ruuhi), comes out summer 2024!
Paula is an interesting protagonist [–]. There is reserved, sharp authority in her that startles with its mysteriousness. The reader knows more about her than the characters of the novel. Still, one secret is kept hidden from the reader as well until the very last pages of the book. And when that information is revealed, at least I put many things into new context, and Paula gets my deep sympathies. The members of Paula’s team also start to ‘gain flesh on their bones’. Everyone has their strengths and weaknesses. The events are carried forth so that elements of the solution are strewn, and motives are shuffled around.
Tuijata, Kulttuuripohdintoja blog