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The globular cluster M15 is unique in its display of star-to-star variationsin the neutron-capture elements. Comprehensive abundance surveys have beenpreviously conducted for handfuls of M15 red giant branch (RGB) and redhorizontal branch (RHB) stars. No attempt has been made to perform a single,self-consistent analysis of these stars, which exhibit a wide range inatmospheric parameters. In the current effort, a new comparative abundancederivation is presented for three RGB and six RHB members of the cluster. Theanalysis employs an updated version of the line transfer code MOOG, which nowappropriately treats coherent, isotropic scattering. The apparent discrepancyin the previously reported values for the metallicity of M15 RGB and RHB starsis addressed and a resolute disparity of $\Delta(RHB-RGB) \approx 0.1$ dex inthe iron abundance was found. The anti-correlative behavior of the lightneutron capture elements (Sr, Y, Zr) is clearly demonstrated with both Ba andEu, standard markers of the {\it s}- and {\it r}-process, respectively. Noconclusive detection of Pb was made in the RGB targets. Consequently for theM15 cluster, this suggests that the main component of the {\it s}-process hasmade a negligible contribution to those elements normally dominated by thisprocess in solar system material. Additionally for the M15 sample, a large Euabundance spread is confirmed, which is comparable to that of the halo field atthe same metallicity. These abundance results are considered in the discussionof the chemical inhomogeneity and nucleosynthetic history of M15.

The Abundances of Neutron Capture Species in the Very Metal-Poor Globular Cluster M15: An Uniform Analysis of RGB and RHB Stars