The laughing policeman (1972)

A mass shooting on a Stockholm bus kills one of Beck's colleagues, making professional investigation and personal uncertainty difficult to separate. Sjöwall and Wahlöö distribute the work among officers with different habits and temperaments, letting an apparently marginal line of enquiry acquire weight. The missing knowledge is partly about their own coworker. Choose it for a compact ensemble case whose momentum comes from comparing and pursuing leads, with anger and grief kept within the working group.