They went in looking for an *explosive belt* that they had been 'reliably' informed was in the house. If, purely by co-incidence, they find evidence of any unrelated crime, they may not even be able to bring charges as the original raid may have been illegal. I don't think knocking the police helps, but I don't think some copper-blogger claiming 'look, we found something else, surely that justifies us!' is much to be happy about.