Will Jussie Smollett Be Investigated by the FBI? Here's What It Takes to Open an FBI Investigation

President Donald Trump tweeted Thursday morning that the FBI and the Department of Justice would re-examine the case against actor Jussie Smollett, two days after Chicago prosecutors dropped all charges against him and expunged the arrest record of the Empire co-star.

It wasn't clear if Trump was annoucing an investigation had been opened, or if he was suggesting that an investigation should be opened into Smollett's claims that he was attacked by two men who threw a noose around him and doused him in bleach.

The FBI's Chicago office did not have a comment for Newsweek when asked whether it had opened an investigation, while the Department of Justice declined to comment.

Can the FBI open the Smollett case after Chicago prosecutors dismissed it? Does the Fifth Amendment's protection against double jeopardy—trying the same person twice for the same crime—apply here? No, because Smollett was never brought to trial for his alleged crimes, so there was never a conviction or acquittal; he was simply cleared of the charges against him.

For the FBI to open a case, it must have reason to believe there was, or will be, a violation of federal law, according to former assistant director of the FBI criminal investigation division Ron Hosko, as reported by The Wall Street Journal in September.

According to the FBI website, the first step in deciding whether or not a crime should be investigated involves a briefing process that explores if a federal offense has been committed, which is not always easy to determine. Take robbery as an example:

"Robbery...is outlawed in every state, but it is not a federal offense unless there is some connection with the federal government, such as the robbery of a federally insured bank," the FBI explains on its website.

While Smollett's potential case was high-profile and remarkably rare—if he did what he was accused of, specifically faking a hate crime, which would be classified as a hoax—investigators may have difficulty finding a federal allegation. Issuing a "hoax threat" could be a federal crime, per the FBI, though this particular violation involves the making or sending of violent threats, not making false claims of an attack to a municipal police department.

The Justice Department also investigates allegations of public corruption, even at the state and local level, if it involves possible violations of federal law. In the Smollett case, the the Justice Department could possibly look into Kim Foxx, the Cook County state's attorney, if it found reason to believe that the decision to drop the charges may have violated the law.

Before Trump's tweet about Smollett, the Chicago Police Union accused Foxx in a Monday Facebook post of acting illegally, and called for a federal investigation. Some Chicago law enforcement officers also planned a protest against Foxx at a public rally on April 1.

This article has been updated to include the Department of Justice's "no comment" response.