According to the U.S. Department of the Interior, an earthquake is caused by a sudden slip on a fault line. The tectonic plates on the fault lines are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking and structural damage that is felt on the surface.

The evidentiary tectonic plates recently shifted in our judicial system when the United States Supreme Court issued its opinion in Diaz v. United States. Justice Clarence Thomas, writing for the majority of the court, held that an expert witness's conclusion that "most people" in a group have a particular mental state is not an opinion about "the defendant" and thus did not violate long-standing rules which prohibit an expert from giving an opinion about the ultimate issue of the state of mind a defendant. According to Justice Neil Gorsuch's dissenting opinion this decision has now "given prosecutors a … powerful new tool. … Prosecutors can now put an expert on the stand—someone who apparently has the convenient ability to read minds—and let him hold forth on what "most" people like the defendant think when they commit a legally proscribed act."