Correction: An earlier version of this article misstated the Prince George’s County Police Department’s homicide closure rate for 2011. The rate was 66 percent, not 63 percent. In addition, because of incomplete information provided by Fairfax County police, the article and an accompanying graphic misstated the number of homicides in that county. There were 11, not eight. The number for Prince William County was also incorrect; it included two cases that were ruled justified. That county had four criminal homicides, according to police, not six. And D.C. police say that one of the 109 homicides recorded in the city in 2011 will be considered a 2012 case because the medical examiner did not issue a ruling until Jan. 1. This version has been corrected.

The District and Prince George’s County had nearly the same number of homicides in 2011, a major departure from a high 20 years ago, when the city saw 325 more slayings than the county.

It is a shift that reflects a double-digit drop in killings in the District from 2010 to 2011, with an especially noticeable downward trend in the most stubborn crime zones east of the Anacostia River. Just across the border, though, the homicide count in the neighboring communities in Prince George’s is surging, and the county as a whole saw a slight increase last year.

There were 97 slayings in Prince George’s in 2011, four more killings than in 2010. In the District, the year saw 108 homicides, down from 132 in 2010 and the lowest homicide total in the city since 1963.

“We share many of the same issues,” said D.C. Police Chief Cathy L. Lanier. “Quite a few of our victims come from Prince George’s County.”

The police department’s 7th District east of the Anacostia River — neighborhoods including Barry Farm and Congress Heights — saw its annual homicide count drop 55 percent, with 24 fewer killings in 2011. Neighborhoods across the border in Prince George’s 4th District — including Hillcrest Heights and Oxon Hill-Glassmanor — saw their count more than double, up by 21 slayings.

Law enforcement officials said the trend along the Prince George’s border reflects problems that migrated with those who left the District for inside-the-Beltway county neighborhoods, including issues connected with poverty and long-simmering neighborhood disputes.

Some D.C. residents who still see frequent violence in their neighborhoods are weary, and say there’s not much to celebrate in the city’s declining homicide numbers.

“I’m slow to get too excited,” said the Rev. Donald Isaac, executive director of the East of the River Clergy, Police, Community Partnership. “As soon as you begin to celebrate, it can reverse so quickly.”

Prince George’s Police Chief Mark Magaw said crime has long run “back and forth” between the District and Prince George’s, and he has pushed this year for increased cooperation between the two police departments.

“It’s one big community now,” he said. “No longer do we have the luxury of saying, ‘We only have to worry up to Southern Avenue,’ ” one of the borders between the city and county.

Though killings in both the District and Prince George’s averaged about two per week during 2011, overall violent crime in the city fell by 10 percent and in the county by 12 percent.

But the city had a 6 percent jump in property crime, largely due to a growing problem with thieves grabbing smartphones, computer tablets and other electronic devices from people and cars. “Snatching electronics is the battle of the century,” Lanier said. “It’s the single biggest problem I have in term of numbers.”

Aiming for fewer than 100

Mayor Vincent C. Gray (D) said that the decline in homicides in the District is encouraging and that the city should work to try to get to fewer than 100 slayings in 2012.

“When people see crime going down like this, especially homicides, they are going to feel safer,” Gray said. “My sense is that people do feel safer. On the other hand, when you still see north of 100 homicides in the city, even though it’s a stark reduction, people are going to continue to be concerned about it. Some additional vigilance is going to serve you well, too.”

Killings in the District have fallen rapidly in recent years, with 2011 bringing the lowest number of slayings in nearly 50 years.

“When I started here in 1990, the two things that used to really bother me was that we were known as the murder capital of the world and the city of unsolved homicides,” Lanier said. “Our detectives and our police officers have done an amazing job turning that around. We are no longer either one of those things.”

Homicides in Prince George’s have been generally trending downward as well, though at a slower pace.

The rest of the region’s suburbs have far fewer homicides than the District and Prince George’s, with most counties recording 2011 homicide numbers roughly unchanged from the prior year. Fairfax County was an exception, with a decrease from 16 to 11.

Though Montgomery County had just 16 homicides in 2011, in March it saw one of the year’s highest-profile murders in the region when Brittany Norwood, an employee at a Bethesda Lululemon yoga store, fatally bludgeoned and stabbed a co-worker, Jayna Murray.

And in the wealthier neighborhoods of Northwest Washington, where homicides are rare, three killings drew wide attention: a teen was shot on a busy street in Georgetown on Halloween night; socialite Viola Drath was killed in her Georgetown rowhouse in August, allegedly by her husband; and in November, a man was gunned down outside a nightclub in Dupont Circle.

The Northeast quadrant of the city, covered by the 4th and 5th districts, ended the year with a combined eight more killings than in 2010.

Area crime watchers say they’ve seen violence steadily shift from the District into Prince George’s.

The migration of many of the District’s poorer residents to inside-the-Beltway communities in Prince George’s has been happening for years, fueled by the District tearing down some public housing, said former D.C. police chief Isaac Fulwood Jr., who led the department in the early 1990s, when the city had nearly 500 homicides a year.

That shift has had lasting effects, he said.

“People from D.C. that had to move tended to move to Prince George’s County, and they took with them the things that poverty brings: Lack of access to everything,” said Fulwood, who is now chairman of the U.S. Parole Commission.

The Prince George’s police department, which has more than 2,000 fewer officers than in the District, was left to deal with neighborhood disputes that people brought with them, as well as new beefs created in the large apartment complexes in Prince George’s.

“Alabama Avenue, Stanton Road subsidized housing, all of that is gone,” Prince George’s Deputy Chief Craig Howard said. “Now when you ride through those areas, there are townhouses, single-family homes.”

Last year’s killings in Prince George’s did not seem to follow any common thread, officials said. Young men and women sometimes killed one another in petty disputes.

The majority of the killings in Prince George’s happen inside the Beltway, a more urban setting than the rest of the county. Because Prince George’s has a larger overall population than the District, its homicide rate was lower than the city’s, with about 11 killings per 100,000 residents, compared with about 17 per 100,000 residents in the District.

Closing cases

Across the nation during the first half of last year, the homicide count increased by about 1 percent for cities the size of the District, and remained the same for counties such as Prince George’s, according to FBI crime statistics.

Lanier, who hoped to have fewer than 100 homicides in the District in 2011, said she remains frustrated by the numbers. “We’re not where we need to be until we have less than 50,” she said.

The Washington Post’s homicide count includes criminal killings within the borders of the city or the county, but does not include killings that officials have ruled justified. Prince George’s homicide numbers last year included one killing investigated by Laurel police and one on the Bowie State University campus.

Lanier said the District had fewer gang-related homicides than in prior years. Most killings happened amid personal disputes, often stemming from squabbles at nightclubs where people had been drinking, she said.

She added that her department’s homicide closure rate is about 94 percent, which sends a message to criminals.

“Word travels pretty quickly when a homicide happens and an arrest is made,” Lanier said. “Your risk of being caught is pretty high if you commit a homicide in D.C.”

Prince George’s police’s homicide closure rate was 66 percent last year, a slight increase over 2010.

In Prince George’s, 16 people were killed in January, including a teenager who used to cook eggs for his 3-year-old brother, an ice cream truck driver and a University of Maryland student who tutored athletes. But by year’s end, overall crime had dropped compared with 2010, with violent crime down about 12 percent and property crime down about 10 percent.

Lanier’s biggest success was in the 7th District, which has regularly led the city in killings and some other crimes. In 1993, the 7th District alone had 133 homicides. Last year it had 20.

“A lot of it is the officers being out there, being visible,” 7th District Commander Joel Maupin said. He said officers continue to take guns off the streets, and often blanket neighborhoods with extra patrols when they get a tip that violence might be coming.

It is essential, he said, to make arrests in crimes such as robberies and burglaries because it prevents future violence.

“Removing these individuals from the streets and doing it quickly reduces crime,” Maupin said.

Isaac, the clergyman who works in the same neighborhoods as Maupin, said his group visits every family that loses someone to violence, offering burial support, grief counseling and other services. “Even if you have one homicide a month, it’s impacting out there,” Isaac said.

Staff writer Mike DeBonis contributed to this report.