The Lagrangists, by Mack Reynolds and Dean Ing (epub/Kindle/pdf)

L-5, a point in the Earth-Moon System where orbits are forever and the new age of Freedom and Plenty can begin. Now, they're trying to kill the man in charge of the first L-5 colony, and Private Eye Rex Bader is the man who will have to find and stop them. But who are the killers? Only time -- and blood -- will tell!