An individual who intentionally makes false accusations against another with the express purpose of damaging the person's reputation can be subject to a variety of punitive measures as permitted by law. Because laws vary by state, civil remedies might differ and are subject to limitations as imposed by state, federal and local municipalities.
TL;DR (Too Long; Didn't Read)
Civil suits allow you to address a variety of false accusations through the court system. False accusations may rise to the level of defamation, which includes libel and slander, and which may include filing a false police report in the right circumstances.
Defamation of Character
Defamation consists of any intentional communication, either in verbal or written form, which is made with the intention to damage a person's reputation; decrease the regard, respect or confidence in which a person is held or to induce negative, disparaging or hostile opinions against a person or organization. To prove a claim of defamation of character, proof of the statement must be shown along with evidence that the individual knew or should have known that the statements were false, but made them with a knowing and willful intent. Defamation is an umbrella term for all types of these statements, including slander and libel, as well as repeating the slanderous or libelous statements of others.
Slander: Starting a Rumor Verbally
Slander, the oral communication of false statements with the purpose of harming an individual or organization's reputation, is grounds for civil action as mandated by state and federal law. For example, sharing a story accusing a charity leader of theft damages both the individual and the organization, perhaps irrevocably. To prove slander, it must be shown through clear and convincing evidence that the individual who is being accused of slander knew the statements that he was making were untrue at the time that he made them and were made with the express purpose of harming the victim's standing in the community or workplace.
Libel: Posting a Lie in Print
Libel is another form of defamation that is subject to civil liability. Libel consists of statements made in print or through visual or Internet-based depictions that present false representations as they relate to an individual or organization's ethics or character. To prove allegations of libel, proof of the false and printed allegations or accusations must be presented along with evidence that the libelous statements were not only insulting or offensive, but defamatory and made with willful intent and with malice. Posting that a man, perhaps your direct competitor in business, is guilty of burglary on social media without that accusation being proven in a court of law is libelous.
Negligent or Incompetent Testimony
In certain circumstances, negligent or incompetent testimony made on the part of an expert witness in a civil or criminal matter may be grounds for civil suit if it can be shown to have harmed the victim's reputation or standing in the community or the victim's workplace. Depending on the nature of the negligent or incompetent testimony, the victim may sue for lost wages, pain and suffering, and in some cases, punitive damages.
Criminal Sanctions for False Police Reports
Intentionally making a false accusation to law enforcement with the purpose of damaging an individual's reputation or to encourage the wrongful prosecution of a party is a criminal offense and may incur criminal charges. Intentionally filing a false report is considered a crime in every state, and the accused may be charged with misdemeanor or felony charges, depending on the nature of the offense. If you accuse someone of a crime you know they did not commit, such as cutting car tires, and the police can prove you knew the case was false, you could be charged with filing a false police report. When criminal charges are proven, a civil lawsuit can easily follow.