The most desirable features in a spectroscopic material are high sensitivity and high resolution. Cerium-activated crystals of lanthanum bromide (LaBr3:Ce) have higher sensitivity and better spectroscopic resolution than sodium/cesium iodide (NaI/CsI) crystals because of higher density (5.29 g/cm3), faster decay time (35 ns), minimal afterglow, and larger (63 000 photons/MeV) and more linear light output (6% nonlinearity over the energy range between 60 and 1332 keV). Of all the recent scintillator materials manufactured to date, LaBr3, with cerium activators, is one of the most promising for high-resolution, fast timing techniques as applied to medical image reconstructions or associated particle imaging.