As pohnpei397 stated, the Fifth Amendment to the United States Constitution extends many due process protections to people involved with the US legal system. I will provide some more detail on the last section of the Amendment:
nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use without just compensation.
This section is important to individual liberty because it (in theory) prevents the government from arbitrarily killing, imprisoning, or confiscating property from anyone without adhering to fair and legal measures. Similarly, this section prohibits the government from confiscating private property to use for public use (such as building a highway or a park) without paying the owner a fair price for the property.
I say "in theory," because some people believe the practice of "civil asset forfeiture" violates the Fifth Amendment by allowing the government to confiscate suspicious property (such as large amounts of cash found in a vehicle) and keep it, even if they do not charge the owner with a crime. Owners must, essentially, sue the government agency and prove their innocence to reclaim their property; many people believe this treats citizens as guilty until proven innocent and thus denies them due process. This debate will likely result in future Supreme Court cases, as it is the Supreme Court's role to determine whether government policies violate the Constitution.