Je suis certaine que vous savez que si un procureur se montre strict envers la police et explique qu'il n'acceptera pas les preuves obtenues de manière illégale, cela incitera fortement la police à utiliser des moyens légitimes.
As I'm sure you know, if a prosecutor is strict with the police and explains that he will not accept evidence that hasn't been obtained by lawful means, there's a strong disincentive for the police to use those unlawful means.