The number of homicides in 30 US cities declined in the first half of 2023 compared to the first half of last year but has remained above pre-pandemic levels, according to a report released Thursday by the Council on Criminal Justice.

The report analyzed homicide data from cities that make it readily available, including New York, Atlanta and Chicago. In the 30 cities examined, homicides declined 9.4% in the first half of this year compared to the first half of last year, with about 200 fewer homicides in that period.

Twenty cities recorded a drop in homicides in that period, while 10 cities saw an increase, the study found. Raleigh, North Carolina, saw the steepest drop of 59%, while Lincoln, Nebraska, saw a 133% increase in homicides.

Additionally, the study said a snapshot of its findings "suggests that levels of nearly all offenses are lower, or have changed little, in the first six months of 2023 compared with the same period in 2022."

Gun assaults, defined as aggravated assaults committed with a firearm, committed during the first half of this year are 5.6% lower on average than during the same period last year, "representing 514 fewer gun assaults in the cities that reported data," the report found.

The one major exception is motor vehicle thefts, which have continued to increase in numbers, according to the study.

"There were 33.5% more motor vehicle thefts from January through June 2023 compared to the first half of 2022," the report said.

That likely relates to a major spike in car thefts of certain vulnerable Hyundai and Kia models as part of a viral social media trend. The two automakers agreed in May to an estimated $200 million class action legal settlement over claims that many of the companies' cars and SUVs are too easy to steal.

Overall, this year's crime numbers are still high compared to pre-pandemic crime levels, the report said. Most "violent crimes" -- described in the report as homicides, aggravated assaults, gun assaults, domestic violence and robberies -- committed in the first six months of 2023 are generally higher than pre-pandemic levels in 2019.

"There were 24% more homicides during the first half of 2023 than during the first half of 2019 in the study cities," a summary of the report said.

Property crime trends have been more mixed. There were fewer residential burglaries and larcenies and more nonresidential burglaries in the first half of 2023 than during the same period four years earlier, according to the report.

The exact causes of any rise or decline in violent crime are difficult to state with confidence. Still, criminologists who have studied the rise in violence over the last few years generally attribute it to the mass societal disruption caused by the Covid-19 pandemic as well as the social unrest and distrust of law enforcement from the police killings of George Floyd, Breonna Taylor and other Black Americans.