The U.S. Supreme Court refused to void an Arizona law that allows certain criminal trials to be conducted with juries of just eight people. The vast majority of states in the U.S. require 12 people.

Arizona courts had rejected an argument that a person is entitled to a 12-member jury. An appeal went to the U.S. Supreme Court, but it affirmed lower court decisions, and there is precedent. 

A similar Florida law was scrutinized in 1970 when the Supreme Court decided to leave it alone. But neither decision sits well with Justice Neil Gorsuch. 

Gorsuch called both decisions a mistake, citing centuries old English tradition of 12-member juries, and therefore that number was clearly the intent of Congress when it wrote the Constitutional amendment.

He also says there is evidence that suggests that smaller juries are less likely to have effective group deliberation and raises doubts about the results.