The Fifth Amendment is important because it specifies legal safeguards for the criminally accused that are designed to protect citizens' life, liberty and property. Among these safeguards are protection against multiple trials for the same crime and the right to refrain from presenting self-incriminating testimony.
The first of the Fifth Amendment's five clauses stipulates that no one can be tried for an "infamous crime" unless indicted by a grand jury. The Legal Information Institute at Cornell University explains that federal law establishes the grand jury number as between 16 and 23, and that grand jurors are selected from the pool of prospective jurors who could serve in any juror capacity on a given day. Infamous crimes are those that are punishable by more than year in prison.
The Legal Information Institute observes that the Double Jeopardy clause protects defendants from successive trials for the same act by providing that they will not be prosecuted for the same crime following an acquittal or conviction.
The Fifth Amendment also protects defendants from having to offer self-incriminating evidence in court. Due to the Supreme Court case Miranda v. Arizona, the self-incrimination clause extends to other legal proceedings like police interrogations.
The Due Process Clause requires the government to respect all rights, protections and statutes before depriving anyone of life, liberty or property.
The Just Compensation Clause obligates the government to compensate individuals fairly when it takes property under its power of eminent domain.