The District finished 2010 with 131 homicides — a 9 percent reduction from 2009 and the lowest number of killings in the nation's capital since 1963. ... Montgomery County saw an increase from 13 homicides in 2009 to 17 last year. ... Fairfax County also recorded a modest increase, from 14 killings in 2009 to 16 last year, while Arlington County recorded one killing last year compared with two in 2009. For the District, the continued declines in homicides during this decade to nearly half-century lows are impressive. The city less than 20 years ago recorded 482 killings, when turf...