WASHINGTON — Crime levels fell last year compared to 2009, continuing a downward trend that had a 5.5 percent drop in the number of violent crimes last year and a 2.8 percent drop in the number of property crimes.

Figures released by the FBI today also showed that there were declines in all four categories of violent crime in 2010 and all categories for property crime went down as well.

“In a word, remarkable,” said James Alan Fox, a criminologist at Northeastern University. In Fox’s view, the declines signify success for aggressive law enforcement and corrections programs and comprehensive crime prevention efforts.

Violent crime last increased in 2005. Property crime last increased in 2002.

The bureau’s preliminary statistics for 2010 are based on information from more than 13,000 law enforcement agencies.

Nationally, murder and non-negligent manslaughter declined 4.4 percent, forcible rape decreased 4.2 percent, robbery declined 9.5 percent and aggravated assault was down 3.6 percent.

The downward trend for murder and non-negligent manslaughter was especially pronounced in the nation’s smallest cities, where it went down 25.2 percent for cities with less than 10,000 people. Murder actually rose 3 percent in cities with populations of 250,000 to 500,000.

In regard to property crimes, motor vehicle theft showed the largest drop in 2010 — 7.2 percent.