Comparison between the total density slope, γ_tot, at the effective radius for CSWA 31 (colored squares) and the sample of group-scale lenses from Newman et al. (2015) (gray squares). The total density slopes inferred from our three reference models are shallower than the average values of other group-scale lenses. The discrepancy between lensing-only models and model Img-MP (L/D) is primarily caused by differences in the best-fit group halo component.