Violent crime in Loudoun and Fauquier counties declined last year to its lowest point in at least six years, according to FBI statistics released this week.

The number of violent crimes in Loudoun dropped 36 percent from a year earlier, Fauquier had an 18.4 percent decline and Leesburg's total was down 40 percent.

When Loudoun's explosive population growth is factored in, the county's incidence of violent crime has dropped by more than half over the past five years.

Loudoun County Sheriff Stephen O. Simpson said the statistics from the FBI's Uniform Crime Report are a welcome indication that some of the new policing measures he and his force have put into place are working.

"We're being as aggressive as we can in implementing some of our initiatives, such as the gang unit and community policing, and I really believe it's had an impact," Simpson said Tuesday. "With a county growing like Loudoun County, we decided we needed to be more proactive instead of being reactive."

Part of that effort came through hiring, Simpson said: While Loudoun's population has increased by about 40 percent since 1999, the FBI figures show that the county has increased the police rolls by 56 percent over the same period.

Simpson noted that although crime in the county is declining, the number of police calls continues to rise. He suggested that plays a part in keeping people safe and underscores a need for Loudoun to remain vigilant about continuing to add deputies.

The annual FBI report, released Monday in Washington, tracks the number of violent crimes -- murders, rapes, robberies and aggravated assaults -- and property crimes -- burglaries, larcenies and thefts, arsons and car thefts.

The drop mirrored a broader, although considerably milder, trend in the region and the nation. Violent crime in the Washington area declined 7.6 percent from 2003; nationally, the decline was 1.2 percent.

Because of a change in the FBI's reporting criteria, it is impossible to compare numbers before 1999 with the new ones. Each year beginning in 1999, however, the number of violent crimes in Loudoun exceeded 200. Last year the total was 140 -- one murder, 27 rapes, 36 robberies and 76 aggravated assaults. The last category is down more than half from the 154 aggravated assaults reported in 2003.

Fauquier reported no murders, three rapes, six robberies and 53 aggravated assaults. Leesburg reported no murders, 13 rapes, 11 robberies and 39 aggravated assaults.

Even the incidence of violent crime -- the number of crimes per 1,000 residents -- was good news for Loudoun. The county's population growth, combined with the drop in crime, enabled the county to cut its rate of crimes per 1,000 residents to 0.59 last year. It was 1.23 in 1999.

"I do consider it a safe community," Simpson said. "That's why people move to Loudoun County, why they live in Loudoun County -- because they consider it safe. We want to do our part to keep it that way."

The incidence of violent crime in Fauquier, in comparison, was unchanged -- 0.98 crimes per 1,000 residents in both 1999 and 2004. Leesburg's incidence dropped to 1.87 crimes per 1,000 residents last year, compared with 2.68 in 1999.

The only sobering note in the Loudoun data was the number of rapes -- 27, up from 23 in 2003. That increase accompanied a national trend. In Fauquier, aggravated assaults increased from 51 in 2003 to 53 last year. Every other category saw a decline.

Both Loudoun and Leesburg had declines in the number of property crimes. Loudoun's count dipped about 13 percent, to 2,667 from 3,065, and Leesburg's dropped about 9 percent, to 849 from 925. Fauquier reported seven more property crimes last year, for a total of 674.