  We present an update of a spectroscopic follow-up survey at low-resolution of
a large number of RR Lyrae halo overdensity candidates found in the southern
sky. The substructure candidates were identified in the RR Lyrae catalog of
Torrealba et al. (2015) using Catalina Real-time Transient Survey (CRTS) data.
Radial velocities and mean metallicities have been estimated for target stars
in almost half of the original overdensities to assess their potential
membership to coherent halo features.
