Free will and ethics
In our society, there are three types of judgments that we make:
1. We come to a decision or a judgment about what actually and factually occurred;
2. Based on what we decide happened, we judge a person's moral culpability;
3. We come to a decision or a judgment about what to do with a person that factually broke a law.
Only the second one above should be affected by any lack of free will. We should not comment on a person's morality if they were compelled to act the way they did. However, determinism does not mean that we need to throw away our judicial system entirely. This is true for the following two reasons:
1. The judicial system itself is based on determinism in that is predetermined that if one performs certain acts, then society will respond in certain ways;
2. If a person has performed illegal acts because the person's genes and environment compelled them to act that way, then a change in environment can prevent that person from engaging in the same antisocial acts again.
The real question regarding free will and ethics is what environmental changes are best to bring about the behavior which is favorable to society and the individual. The justice system needs reform to take determinism more into account, but determinism's existence doesn't necessarily mean we need to throw the justice system away.