  We derive photoelectron selection rules along the glide plane in orthorhombic
Bi_2Sr_2CaCu_2O_{8+\delta} (Bi2212). These selection rules explain the reversed
intensity behavior of the shadow and the main band of the material as a natural
consequence of the variating representation of the final state as a function of
k_\parallel. Our one-step simulations strongly support the structural origin of
the shadow band but we also introduce a scenario for detecting
antiferromagnetic signatures in low doping.
