Murder on Mars

Murder on Mars is a juvenile science fiction novel, the sixteenth in Hugh Walters' Chris Godfrey of U.N.E.X.A. series. It was published in the UK by Faber in 1975. It was the second in the series to switch to detective work rather than space exploration.

Plot summary
In a crater on Mars an engineer from Mars Base has been found dead, his spacesuit slashed. Despite having a large number of suspects to interview, Morrey Kant, Serge Smyslov and Tony Hale's questioning flushes out a prime suspect. But Tony does not believe they have the right man and hatches a dangerous plan to find the real killer.