In over 30 years as a Seattle defense attorney, I have defended people accused of all sorts of crimes from DUI to murder, clients occasionally ask me: "do you believe I am innocent?" Typically the defendant who asks that tends to be experienced--perhaps in the wrong way. That is, they've been here before. So it is a delicate question usually asked by an indelicate sort. But they believe that their lawyer must believe in their innocence to do a good job.
Why is it a delicate question? Our criminal justice system would be utterly corrupt and unable to function if most accused people were totally innocent, as opposed to most accused having done something, as is the case. The police and the prosecutors are, by and large, honest, hard working people. They would not last in their jobs long if most people they arrested and prosecuted had not done something. Nor could their budgets sustain that..!
The system may presume defendants innocent, but to hold someone to answer to a charge, there must be probable cause. That is, there must be witnesses, evidence, forensics and so on that establish the case. Probable cause is not a high standard--are there specific facts and circumstances to support a reasonable probability that the accused committed the crime? Even with that low standard, most honest prosecutors will not file a charge unless they believe they can prove it beyond a reasonable doubt to a jury. Given that background, I would be dishonest if I told most criminal defendants that I believed they were innocent..
Yet if a lawyer tells a client, "I don't believe you're innocent," the client is likely to lose faith in their lawyer. So how is this answered? One simple answer is "my belief is irrelevant." I am here to defend you, to analyze all the evidence in your case, to see if there are legal or constitutional issues, and to determine if the case can be proved beyond a reasonable doubt. If I find some defense or legal issue, my job is to pursue that as far as I can to either mitigate the punishment or beat the charge. So my belief is irrelevant. It is up to a jury or a judge to 'believe' if you are innocent or guilty. If my beliefs intruded, I might not zealously defend you. You don't want my beliefs--my personal prejudices or preferences--to motivate me, do you? No, you want an advocate who looks under every rock in the case to find a flaw, to push the envelope, and to work until every possibility is explored, not a lawyer who works on 'belief.' If lawyers had to 'believe' their clients were innocent to defend them, few people would be defended very well..
This leads to the inevitable cocktail party question: "how can you defend those people?" In some ways it is easier to defend guilty people. If a person is truly innocent, it makes me worry a lot more since there is always a possibility that an innocent person can be convicted. I would hate to have that on my conscience: I let an innocent person go to prison. No, if all my clients were innocent, I would never sleep..
As for the rest, it is not my job to determine if they are guilty or to punish them. My job, as our adversarial system requires, is to defend them to the best of my abilities. It is the police and prosecutor's job to try to prove they are guilty. It is the jury's job to determine if it is proven. And it is the judge's job to punish in the event guilt is proven. If our system is to function fairly, and if I am to contribute in any way to the rule of law, then everyone, including drug dealers or sex offenders, not just the rich and powerful, deserves their day in court and the best possible defense. Aren't tobacco companies just well funded, age old drug dealers? Crack cocaine dealers are less insidious in a way--they don't fund dubious research to show how safe crack is. No, as long as tobacco corporations and their ilk can litigate their interests in court to defend their assets and interests, I have no problem defending "those [guilty] people.."
If "those people" don't feel that they had the best possible defense, then what will they think when they are in prison? Won't they blame their lawyers for not doing the job? Won't they be bitter and believe only the rich, or the OJ's, can beat the system? What kind of people will they be upon release from prison? They won't blame themselves. But if they did get the best possible defense, and they know it, then the blame for going to prison may be directed elsewhere. And perhaps rehabilitation will follow..