“Whoever commits an offense against the U.S. or aids, abets, counsels, commands, induces, or procures its commission, is punishable as a principal.” 18 U.S.C. 2

Legal and linguistic experts have been debating who may have been guilty of criminal wrongdoing arising out of, ironically, the emails, tweets, and blocked phone calls of Donald Trump, his family and staff.

Was it collusion—per Webster, a “secret agreement between two or more persons for a fraudulent or deceitful purpose”? Or perhaps conspiracy—defined in legal texts as two or more people agreeing to commit a criminal act when there is an overt act in furtherance of that agreement, not necessarily completion of the crime envisioned—is closer. If the Russians were guilty of conspiring to commit specific crimes, how might the president’s aides and boosters also be?

When I was an organized-crime prosecutor in Robert F. Kennedy’s Justice Department, I tried a criminal case that ultimately went to the Supreme Court, and its ruling sheds light on the current debate regarding these meetings between Donald Trump and others, and with the Russians. The ruling deals with the second section of the federal criminal code noted above—not some exotic or vaguely defined crime.

I am reminded of that notorious case I tried, and retried, the ultimate conviction upheld by the U.S. Supreme Court, because it is relevant to the present debate about collusion v. conspiracy. In U.S. v. Lester, et.al., the government indicted three police officials, two gambling operators, and a lawyer under the civil rights law (18 USC 242) for depriving citizens of their civil rights when acting under color of law. The case involved a conspiracy to falsely arrest and disgrace George Ratterman, a former football star running for sheriff of Newport, Kentucky, then described as a corrupt “sin city.” Ratterman was running to clean up the town, and the defendants tried to frame him in a compromising act with a stripper.

Our first trial ended in a hung jury. I retried it, and we convicted the lawyer and one of the gambling characters. The jury acquitted the other casino operator (later convicted of another crime) and the three policemen. The case was appealed on the theory that the two who were convicted weren’t and couldn’t be acting under color of law; that standard could only be applied against the three acquitted policemen. Interesting theory.

In 1966, the federal appellate court upheld the conviction of the two men found guilty. But here’s the interesting part. It noted in passing that the evidence was sufficient to convict all six. The Sixth Circuit ruled that the two appellants were guilty of aiding and abetting the three police officers. The two convicted defendants could be guilty of aiding and abetting a conspiracy, even if they could not commit the substantive civil rights offense that was the object of the conspiracy.

The appellate court ruled that under 18 USC 2, which by the way is still law, whoever “aids, abets, counsels, commands, induces, or procures its commission, is punishable as a principal.” If he “causes an act to be done by him or another,” that would be an offense against the United States, and he would be punishable as a principal.

Ignorance of the law, as all know, is no defense. Nor is the incompletion of any planned conspiracy. To quote the court:

“…even though a defendant was incompetent to commit the offense as principal by reason of not being of a particular age, sex, condition, or class, he may, nevertheless, be punished as a procurer or abettor.”

A recent Politico survey of law professors offered a list of crimes that might result from facts already made public about Russia’s involvement in the 2016 election: violations of election and campaign financing laws, foreign intelligence activities or cybersecurity prevention laws, wire fraud, something we lawyers call misprison of a felony, false filings and false statements to government officials, the Computer Fraud and Abuse Act, perjury.

Might the Lester precedent apply to the acts of Donald Trump or Donald Trump, Jr., Paul Manafort, Jared Kushner, their consorting lawyers and staffers in the private sector, the campaign, or the government? If the Russians violated any of the laws, might these Americans—possibly the president—have aided and abetted them?

The law that the appellate courts relied on in my case is venerable, going back to the 14th century, and courts have cited modern applications of it. Might the current, up to the moment, “breaking news” controversy be the latest and most profound application of the Lester case ruling? Depending on what the special prosecutor already knows and the facts and evidence he develops, my old case just might come back to life.

That case was notorious and exciting when we tried it. RFK called and found me and the FBI agent I worked with at the small restaurant in Newport, Kentucky, where we were having our modest celebratory lunch to congratulate us. Now half a century later, might this case turn out to be the precedent to bring down a president?

Ronald Goldfarb is a Washington, D.C., attorney and author who served in the RFK Department of Justice.