There is a strong argument for them to still refuse: suppose the suspect somehow gamed the system (e.g. by translating the voice via radio), and the suspect is

There is a strong argument for them to still refuse: suppose the suspect somehow gamed the system (e.g. by translating the voice via radio), and the suspect is acquitted based on this data, and proceeds to do his evil things — think about the bad PR your company would get! No thanks, I'd rather stick to the safe and rather popular policy of preserving privacy.