Let's be clear. As defence barristers we sometimes represent the most dangerous, most ruthless people in society. Criminals who will cynically manipulate the truth and the courts to secure their own acquittal, only to return to the street to ply their socially destructive trades. That happens. But this is not the point. As lawyers we are not here to judge our clients. That's your job, as their peers on the jury. It is our job to mount every legitimate defence on their behalf, unpalatable or not.
And, in these games of moral and mental gymnastics, the police have a pretty thankless job. Those officers who strive within the law to arrest serious criminals deserve our gratitude. No reasonable person disputes this. However, this is far from the whole story. For we are faced with an ethically dangerous mutation of police corruption that offers a telling clue about the state of the criminal justice system itself.
The more familiar type of corruption, being "bent for yourself", is using the job as a perquisite. Like the Met officer imprisoned for stealing from the home of a murder victim. Kickbacks, skims, backhanders, protection money. Unofficial income support. These officers have evolved from the sub-species of pond-life who once stole from their mother's purse. Of course, it is unsurprising that some flawed souls succumb to the all pervasive temptations of money and drugs that their job uniquely presents. That happens too.
But what about this other breed of corrupt officer, the cop who is "bent for the job"? Once a decent youngster who saw policing as his sacred mission, we find him disillusioned after a decade or more of frustrations. And he has convinced himself of the truth: the law protects the guilty, it cannot deliver justice, it makes his job, his life, meaningless.
Consider the dilemma. After two years hard work, you've finally rearrested Jimmy Madden for murder. Last time round, Madden walked, by quite dishonestly alleging that you "fitted him up". You were crucified by Madden's QC. Then, after Madden was released, he committed his second murder. Of courageous young Laura Hope, who defiantly testified against him in the first trial. But you're going to avenge the memory of Laura Hope. You've got him - or so you think.
As trial approaches, terrified witnesses "disappear" themselves. Madden's DNA sample is contaminated in the lab. A video is accidentally wiped. Your case is "off the record" - like a pro taunting his nemesis. If he walks, he will kill again. But now you can stop it. A few words against a life. That's why you became a cop isn't it? To protect. Madden is laughing at you, laughing at the memory of Laura Hope who trusted you, he's laughing at the law.
So you do it. You testify. And he's convicted. Once inside, his enemies and rivals finally catch up with him. Jimmy Madden is no more. But is justice done? For you now discover that Madden didn't murder Laura Hope. Her jilted lover did. And he's confessed. Now it's too late for you to remember that you swore to serve the law, not to be above it. To uphold it, not to take it into your own hands.
So we may just about understand officers who are "bent for the job." But we can never turn a blind eye to their misguided "heroics". They are breaking the law. They are, to use that old legal technicality, mere criminals.
Dexter Dias is the author of `Above the Law' (Coronet, pounds 7.99)