With this year three quarters over, the number of homicides in the District has fallen well below last year’s rate, which was the lowest in decades.

As of Friday, 81 people had been slain in the city — more than 15 percent fewer than the 96 homicides reported by the same time last year — according to police figures.

If the rate of killings in the first nine months continues through December, the homicide figure for the year would be 108, compared with 132 last year.

In falling below last year’s pace, the homicide figures continue a downward trend that has characterized most of the years since the late 1990s.

As recently as 1993, the number of homicides was 454 — more than three times as many as last year. The level last year was the lowest in more than four decades. (In 1963, the figure was reported as less than 100.)

In discussing the reasons for the decline in 2010, D.C. Police Chief Cathy L. Lanier cited relationships with community members and technology that places vital information, including photographs and warrants, at the disposal of officers on patrol.

In addition, police have said they have altered their tactics, including shifting their focus from volatile locations toward people known to be gang members or offenders.

Last year, the number of homicides declined not only in the District but also in Prince George’s County, adjoining jurisdictions that have the highest crime levels in the Washington area.

This year, however, the number of homicides in the county has risen.

Including justified killings and fatal shootings by police, the figure in Prince George’s at one point last week was 85, compared with 76 last year. County officials have said that much of the increase stems from a spike in violence in January.