Novel interference effects are observed in the Auger resonant Raman transitions of core-excited HF. Pronounced oscillations, controlled by detuning above the resonance maximum, appear in the spectator decay spectra of the dissociating molecule. Using predictions from the time-dependent theory of the resonant inelastic Raman scattering, these observations are explained by a favorable spatial localization of the nuclear wavepacket in the intermediate state during its creation. This phenomenon should occur whenever photoexcitation, electronic decay and nuclear dynamics have comparable time scales. (C) 2004 Elsevier B.V. All rights reserved.