Junk Science or Relevant Evidence: Supreme Court Says Experts May Now Aid in Determining Criminal Intent

In criminal cases, oftentimes the most significant element in dispute is whether the defendant harbored the intent to “knowingly” or “willfully” violate the criminal law at issue. If the defendant denies that he knew what he was doing was illegal, the government must prove beyond a reasonable doubt that the defendant had the required mens rea — or mental state — to violate the law. The government does this by presenting circumstantial evidence that it argues supports a reasonable inference that the defendant had the required mental state to violate the law. And defense lawyers test that evidence largely on cross examination and by presenting counterevidence. 

The more complicated the law — think tax, securities, or federal election conduit contribution laws — the riskier it is that a person can be held criminally liable for what seemed like innocent or at least not illegal conduct. In these cases, experts may be called to testify about how a certain industry or…