In the film Bridge of Spies, Tom Hanks plays the American lawyer James B Donovan, who defended a man accused of spying for the Soviet Union in the USA in the late 1950s. He is called unpatriotic and he receives hate mail and threats to his life. Someone fires a gun at his house. No one expects him to put much energy into the case, but he does and he fights for his client as hard as he can. When he is incredulously asked why, he just says ‘everybody matters’.
That simple phrase sums up what criminal lawyers believe in. Equality before the law is another way of putting it, but ‘everybody matters’ is better.