There was a case where a German police officer threatened to torture a known child abductor and suspected murderer to get hold of the location of the child. The threat was effective, the child already dead, the officer reported himself. Before court, the officer and a subordinate got away with a fine of 90 respectively 60 days of disposable income (that's the standard rate for a day in prison in Germany), on probation. Reasoning for the mere slap on the wrist was (aside from them reporting themselves) that while completely illegal the threat was indeed conscionable, done out of a motive to protect. The defence argued self-defence (which in German law doesn't only extend to yourself but others), but courts would never go for that that in case of police officers that slope is too damn slippery. Parents, different thing.