The combination of excellent space-based remote sensing, and image reconstruction techniques, as well as improvements in numerical modeling, help enhance our understanding of particle transport in solar flares. We conduct a rigorous analysis of flare hard X-ray emission using the unprecedented spectral and spatial resolution of the RHESSI telescope data in order to better understand the spectral properties of the emitting electron population in solar flares. We complete our study with a forward-fit to the data using a Fokker-Planck kinetic code, to numerically model the particle transport in phase-space in realistic magnetic geometries and for different particle injection profiles.