President Donald Trump’s personal attorney Michael Cohen said Wednesday he would plead the Fifth Amendment, his constitutional right against self-incrimination in a lawsuit filed by adult film actress Stormy Daniels, who says she had an affair with Trump.

In a filing in Los Angeles federal court, Cohen said he would assert his constitutional right after the Federal Bureau of Investigation (FBI) raided his office and home earlier in April. Daniels, whose real name is Stephanie Clifford, sued Trump and Cohen to invalidate a non-disclosure agreement which she signed days before the 2016 presidential election. She said she wants to be able to discuss the alleged affair with Trump, which he denies.

What exactly is the Fifth Amendment?

The Fifth Amendment of the United States Constitution is the section of the bill of rights that protects citizens from being imprisoned for committing a crime unless they have been indicted by the police. It also stipulates that no one can be put on trial for a serious crime, unless a grand jury decides that there is enough proof of evidence to require a trial. If there is enough evidence, an indictment is then issued, which means that the person who is accused of a crime can be put on trial. Individuals from the military can go to trial without a grand jury deciding that it is necessary, if the alleged crime is committed during a national emergency or a war.

What is relevant to Cohen is the fact that the Fifth Amendment also states: “No individual can be compelled in any criminal case to be a witness against himself.”

In essence, it means the government does not have the power to make someone testify against oneself. That is why a trial uses evidence and witnesses, instead of testimony of the accused.

Famously, the Fifth Amendment has been used in the past by Kenneth Lay, the CEO and chairman of Enron Corporation, an American energy, commodities, and services based company in Houston, Texas. The company declared bankruptcy on Dec. 2, 2001, and was charged with keeping fake accounts and fooling regulators. Lay told the Congress he wanted to tell his version of the story of the company’s financial collapse, but he soon changed his mind and pleaded the Fifth Amendment when he was called before the United States Senate Committee on Commerce.

Kenneth Lay Former Enron chairman Kenneth Lay leaves the Bob Casey U.S. Courthouse for the midday break of his fraud and conspiracy trial in Houston, Texas, April 25, 2006. Photo: Photo:Getty images/Dave Einsel

In another famous case involving the Fifth Amendment, Ernesto Miranda was arrested on March 13, 1963, in Los Angeles on the basis of circumstantial evidence that linked him to the kidnap of an 18-year old girl. Police officers interrogated him over two hours until he signed a confession. His attorney claimed that the confession was not voluntary and that he was not aware of his legal rights. Miranda was sentenced to 20-30 years on the basis of that confession, but Federal Supreme Court Chief Justice Earl Warren ruled the interrogation to be in direct violation of the Fifth Amendment, and overturned the conviction.

Cohen pleading the Fifth Amendment in this case is completely in line with Trump’s statement in 2016, when he stated that a criminal investigation would handcuff the next president and hurt the country. Such an investigation was therefore to be avoided at all costs.