On Wednesday, Mr. Hicks’s lawyers asked no questions of Professor Sommers.
One reason that some bias crimes are not prosecuted under hate crime laws is that defendants like Mr. Hicks already face the steepest possible penalties, said Brian Levin, director of the Center for the Study of Hate and Extremism at California State University in San Bernardino.
In 2015, the Hicks case landed on the desk of Ripley Rand, then the United States attorney for the Middle District of North Carolina. In an interview this year, Mr. Rand said the federal government was meant to intervene if local authorities could not or would not do their jobs, which did not seem to be the case in Durham, where Mr. Hicks had seemed destined to spend the rest of his life in prison.
Mr. Rand said he had told the families back then that the blurred motives complicated the application of the hate crime law, and was surprised to learn that they were still waiting for public recognition that the murders were motivated by hate.
“I have failed the family in not making sure the family fully understood the law,” he said.
The family appealed to Vanita Gupta, then the assistant attorney general running the Justice Department’s Civil Rights Division, who met with them twice. Ms. Gupta declined to discuss the case but, speaking generally, explained that the department was governed by a Sixth Circuit decision that did not allow for mixed motives, setting what some experts said was a higher bar than the law requires.
“The proof must be very clear that the only motivation for the crime is hate,” Ms. Gupta said.
Legal standards, however, are not the same as moral standards. And that, Professor Levin said, is where the victim impact statements come in: as “the moral anchor for what we do next.”
Mr. Hicks had initially asked to be excused from the courtroom before the victims’ family members spoke. “I like to think I’ve got empathy, but I look at the way I act with stuff and really wonder if I do,” he said in an interview. “I feel sorry for the family members, but at the same time I really don’t want to deal with them, and that would be empathy.”
Dr. Abu-Salha objected, saying that letting Mr. Hicks be absent would be “coddling” him.
“In no just world,” he wrote in a letter to the court, “should he be able to murder children and not face the words of the families whose lives he has destroyed.”
After reading the letter, Mr. Hicks withdrew his request to leave the courtroom.