Results are presented on the photolysis of DI at 266 nm. An experimental approach is used that combines narrow-band, velocity-aligned Doppler spectroscopy (VADS) and a constrained detection geometry. Atomic deuterium is detected, and transitions out of the individual nuclear hyperfine states of the ground electronic state (the F states; 0.010 92 cm(-1) splitting) are resolved via the Lyman-alpha transition (similar to82 280 cm(-1)). Consistent with previous work on the hydrogen halides, the D-atom product state distributions are statistical. However, the methodological improvements required to resolve the states bode well for studying other chemical systems with this approach.