PET detector modules that implement depth of interaction information reduce uncertainties about the actual line-of-response after positron annihilation. This, in turn, has an effect in the spatial resolution and uniformity across the field of view of the reconstructed image. It also has an effect on the system sensitivity since it enables the use of thicker crystal with respect to a non-DOI system without deteriorating significantly the spatial resolution. In this work we evaluate a DOI detector design based on a scintillator phoswich of two types of pixelated crystals with different time decay constants. A matrix of silicon phomultipliers (SiPM) was coupled to this crystal array without any light-guide, and its outputs were connected to an anger logic type of charge divider which outputs were buffered using a transimpedance amplifier.