Maj Sjöwall is a Swedish author and translator. She is best known for the collaborative work with her partner Per Wahlöö on a series of ten novels about the exploits of Martin Beck, a police detective in Stockholm. In 1971, the fourth of these books, The Laughing Policeman (a translation of Den skrattande polisen, originally published in 1968) won an Edgar Award from the Mystery Writers of America for Best Novel.They also wrote novels separately.
Someone is killing young girls in the once-peaceful parks of Stockholm -- killing them after having his way. The people of Stockholm are tense and fearful. Police Superintendent Martin Beck has two witnesses: a cold-blooded mugger who won't say much and a three-year-old boy who can't say much. The dedicated work of the police force seems to be leading nowhere, and with each passing day, the likelihood of another murder grows. But then Beck remembers someone -- or something -- he overheard.