It's a checks and balances system. Congress passes laws but it's ultimately up the President, who's decision is ultimately up the Supreme Court.
But a judge can only overturn a jury's verdict if it's guilty to innocent.. He/she can't overturn an innocent verdict to declare to the defendant guilty. So it's in the defendant's favor.
Have you had your coffee today?

I think Jack McCoy was trying to convict the gun manufacturer of manslaughter for not changing the style of the gun so it can't be modified into an automatic weapon after this guy went on a killing spree

what was the crime?

I saw that on an episode of Law & Order ~ the judge felt the jury was going on emotion and not the law

what?

Juries in UK?