Criminal procedure puts the burden of proof on the prosecution. It is up to the prosecution to prove that a defendant is guilty beyond any reasonable doubt. The defense does not have to prove that they are innocent. Any doubt is resolved in favor of the defendant. The presumption of innocence is required in the United States. Basic rights include the right for a defendant to know what offense they have been arrested for or are being charged with.
Defendants have the right to appear before a judge within a certain time after being arrested. In the United States, defendants have the right to legal counsel. The government must provide any defendant who cannot afford their own lawyer with a lawyer paid for at the public expense.