Homicides connected to extremism declined in 2023 for the second year in a row, but risks for extremist violence remain high as antisemitism and domestic terror threats have risen, according to new data.

The big picture: Preliminary figures have shown the U.S. ended 2023 with one of the largest annual drops in overall homicides on record, even as the nation's 10 largest cities saw significant surges in hate crimes last year.

• The ADL Center on Extremism's annual Murder and Extremism report also found that right-wing extremism was connected to all extremist-related killings of 2023.
• White supremacists were tied to the overwhelming majority (88%) of extremist-related murders last year.

Details: Extremists were involved in the killing of at least 17 people in 2023 in seven separate incidents — a significant drop from the 27 extremist-related murders from 2022, an Anti-Defamation League (ADL) analysis found.

• That's also another drop from 2021, when the U.S. saw 35 extremist-related murders.
• In 2021, Lyndon McLeod, an adherent of the toxic masculinity subculture of the "manosphere," killed five people in a multi-location shooting rampage in Denver.

The decrease continues a trend of fewer extremist-related killings after a five-year span (2015-2019), during which the number of extremist-related murders ranged from 47 to 79.

Zoom in: The two deadliest incidents in 2023 were extremist-related shooting sprees by white supremacists: the Allen, Texas, mall shooting in May, and the store shooting in Jacksonville, Florida, in August.

• Firearms were used in almost all of the 2023 extremist-related killings (94%).

Yes, but: Last year was the third straight year of spikes in the big cities' overall average number of hate crimes. It came as the Israel-Hamas war sparked jumps in antisemitic and anti-Muslim hate crimes in the last months of 2023.

• A report by the Center for the Study of Hate and Extremism at California State University, San Bernardino, showed overall increases in hate crimes also extended to major cities outside the ten largest ones, including San Francisco and Boston.

What they're saying: "Our data shows that, while extremist killings have decreased, the threat of extremist mass shootings has not," Oren Segal, vice president for the ADL Center on Extremism, said in a statement.

• "The extremist landscape remains complex, and the threat of deadly extremist violence may be even higher this year as many of the issues animating hate and violence can be exacerbated in an election year."

Between the lines: Hate crimes tend to pick up in the months before a presidential election and at the end of the year around religious holidays, Brian Levin, the recently retired director of the Center for the Study of Hate and Extremism, tells Axios.

• Anti-Jewish hate crimes also have increased dramatically after each news-dominating Middle East conflict in the past 30 years, he said.

What's next: The ADL recommends that the White House should name a senior-level Domestic Terrorism Director at the National Security Council to focus on domestic terrorism and hate-motivated violence.

• It also recommends that federal, state and local officials should ensure that no public employees are involved in violent movements and that those who sympathize with extremists are not in sensitive positions, such as law enforcement.