On one side of Chris O'Leary's house sits an empty apartment building, boarded up since rampant drug dealing closed it years ago. On the other side is the home where O'Leary's 19-year-old neighbor lived until he was shot in an apparent drug dispute in 2008.

It's no surprise to O'Leary that his house sits in the city's hottest crime spot - six square blocks in Frankford that racked up 84 robberies, 69 aggravated assaults, and 3 homicides in three years.

But things are changing, he said.

"It's better now than it was," said O'Leary, who moved to the area 10 years ago. "There was a time in the late '90s when there were three or four guys selling drugs on every corner, and you don't see that anymore."

Police say crime is down in O'Leary's neighborhood and in other rough areas, thanks to crime-fighting strategies and particularly a network of foot patrols that were put in place last year in the city's most dangerous places.

The sector where O'Leary lives, bordered by Frankford Avenue and Arrott, Leiper, and Harrison Streets, is one of 60 hot spots identified in a Temple University study as the city's highest-volume crime areas. Police used the analysis to assign 200 officers to foot patrols across the city. Since the study was completed last year, that number has changed as captains have shifted the patrols depending on each district's needs and the number of officers available at a given time.

Temple's study, which covered three months, showed a 22 percent drop in crime in areas covered by the foot patrols. Arrests were up 13 percent.

As in other major cities, crime has been on a decline in Philadelphia. Violent crime - down in all but three districts - dropped 7 percent citywide in 2009 compared with 2007, with homicide down 23 percent and aggravated assault down 4 percent.

The foot-patrol experiment overlapped with Operation Pressure Point, in which local, federal, and state authorities flooded violence-prone areas on summer weekends. Last year police also unrolled Police Service Areas, which divided districts into small areas to be patrolled by consistent teams of officers. But Police Commissioner Charles H. Ramsey believes the foot beats - six- to 10-block areas instead of the traditional 20 blocks - are a crucial piece in keeping crime on the downswing.

"Foot patrol is one of those ideas that, in some people's minds is a feel-good thing," he said recently, "but if it's sustained, and if it's done intelligently, it can be effective. We set out to show that."

Some criminologists downplay the effectiveness of foot patrols, which can be seen, especially by officers, as preventive and not too exciting.

On a typical day, an officer may return a truant teenager to school, break up loiterers, or stop a car with expired tags. Officers cover the same territory day after day so they can get to know people on the beat, hoping those people will pass on information when crimes occur.

Inspector Daniel Castro, who was captain of the 24th District last year when patrols were assigned there, said he appreciated the accountability of foot patrols.

"You should know what's happening on your beat," said Castro, who walked a beat in Rittenhouse Square in the 1980s and was recently made commander of the Traffic Division. "A robbery happens, you should know everything about it. But you start with the smaller crimes, enforcing the quality-of-life issues, and you're going to get information about everything else."

Ramsey, who started off on a foot beat in Chicago and used the patrols as head of police in Washington, said foot patrols helped officers connect with the public.

"Instead of driving down the street at 30 miles per hour with the windows up, you walk down the street and get to know people," he said.

Ramsey set up foot patrols in 2008 in the city's five busiest police districts, using officers fresh out of the Police Academy. Police soon noticed a drop in shootings, Deputy Police Commissioner Richard Ross said.

"We believed adding foot patrols was going to be effective," Ross said, "but we wanted to measure how effective."

That led to the partnership with Temple's Jerry Ratcliffe, a criminology professor who conducted the study on Philadelphia's most violent street corners.

Ratcliffe and his colleagues analyzed and mapped crime data for 2006, 2007, and 2008, revealing clusters of crime within just a few blocks. Most shooting victims are shot within a few blocks of their homes, Ratcliffe found, and he noted that violence often bred more violence, presumably in the form of retaliation.

"Philadelphia's got really small neighborhoods, and I think many people's lives revolve around a few streets," Ratcliffe said. "When something happens, everyone knows about it, and you can't let people in that neighborhood know you let something slide."

The department asked commanders to tailor the foot beats to each district's problem areas, then deployed officers last March and in July for three-month stints.

Not all officers were enthusiastic, but crime began dropping, and once commanders showed officers that the patrols were having an impact, the mind-sets started changing, Deputy Police Commissioner Kevin Bethel said. More important, officers got to know their territories, he said.

"The street has a pulse, and you have to feel that," Bethel said. "No matter what they think about it, they're better cops for doing it."

The Temple study also found reduced crime in many of the areas adjoining the foot patrols. Crime rose slightly in some bordering areas, but the crime reduction in the patrol areas outweighed those increases in most cases, Ratcliffe said.

After three months, some foot patrols were shifted to other crime areas. But in the city's two most dangerous spots, officers are still walking the streets.

The city's second most dangerous area, according to the Temple study, is a part of Kensington in the 24th District bordered by Kensington Avenue and Somerset, Cambria, and C Streets. The area had 70 robberies, 63 aggravated assaults, and 1 killing in three years.

That parcel and the area in Frankford are beneath the Market-Frankford El, where crime tends to thrive due to a high volume of strangers and loiterers, Ratcliffe said. Both areas bustle with drug dealers and buyers. Pawnshops, liquor stores, and bars add to the potential for trouble, he said.

"Those businesses mean that people will have cash," he said. "Given that these are some of the poorest areas in the city, it's a perfect storm."

Capt. Frank Bachmayer said the foot patrols helped drive down crime in the 15th District, where homicides dropped from 17 in 2008 to 14 in 2009. Both violent and property crime decreased 9 percent from 2008 to 2009, and the district leads the city in truancy enforcement, Bachmayer said.

In Kensington, Castro asked officers in the 24th to volunteer for the foot beats when the experiment was over. To his surprise, seven veteran officers put in for them, as well as a rookie who wanted to continue.

Castro then expanded the area slightly, and got approval to give the officers bicycles, weather permitting.

"They can cover more area while still keeping the foot-beat concept," Castro said. "I'm a firm believer in the concept that putting the right people in the right places will drive crime down."

The 24th had the largest decrease in homicides of any district in the city last year, dropping from 26 in 2008 to 10. Robbery and aggravated assault went down as well.

Residents of the Frankford neighborhood said police seemed to be around more often. O'Leary has seen officers stop to talk to business owners and neighbors, but said it was hard to know whether any changes were permanent.

"The police are making attempts at working with the community, but they really have a tough battle," he said. "People in this neighborhood, they're used to seeing the police show up only to enforce crimes."

Paris Smith, 40, also notices the police presence, though he sees them driving more often than walking. A Frankford resident for 25 years, Smith has watched the neighborhood start to improve and then collapse several times. On each downswing, he said, he sees more people move away.

"It's starting to change again, and that's a good thing," he said. "When good neighbors are chased out by bad people, that's what you don't want. That's the most terrible thing that can happen to a community."

For an interactive look at the change

in violent crime in Philadelphia, go to www.philly.com/ViolentCrimeEndText

INSIDE

Map: The 60 highest- volume crime spots in the city. A15.

Table: Violent crime statistics by police district. A15.EndText

Contact staff writer Allison Steele at 215-854-2641 or asteele@phillynews.com.