In a previous paper (J. Phys. Chem. 1994, 98, 3444), we showed, within the framework of the reaction coordinate representation of the dynamics of a chemical reaction, that application of a complex scaling transformation to the reaction coordinate leads naturally to the definition of transition states with complex energies and to the definition of an operator whose expectation values are the lifetimes of these states. That analysis has the unphysical feature of not eliminating the dependence of the lifetime operator on the positive angle parameter of the unitary transformation that generates the scaling of the reaction coordinate. In this paper, we reexamine the approach used earlier and remove this unphysical feature of the analysis. We recover the results of our earlier analysis and provide an interpretation of other related results in the literature.