Like many stretches of Camden's notorious Whitman Park neighborhood, crime blooms around the 1500 block of Louis Street. With seven vacant houses in less than a tenth of a mile, the area has been the scene of at least two recent fatal shootings, and, since late 2012, police have seized more than 400 bags of marijuana, cocaine, crack, and heroin, thousands in cash, and six illegal guns within a one-block radius. A year ago, after neighbors told police they feared one empty house on the block had become a haven for illegal activity, officers raided the building and found a safe loaded with a shotgun and drug paraphernalia.

According to police and to an extensive survey of all the city's properties, that house is one of four vacant structures on that side of the street. But on one morning last week, a man stood in front of it protectively and claimed it wasn't abandoned.

"That's not empty. Somebody lives there," he said. Then he added forcefully, "You need to get . . . out of here."

Next year, as Camden leaders move forward with a plan to demolish 596 of the city's most dilapidated properties, six of the buildings on the 1500 block of Louis Street will be torn down, forcing any unofficial inhabitants to move elsewhere. The houses to be razed make up what city spokesman Vincent Basara called "the worst of the worst," and few will be sad to see them go.

"We hear it from the neighborhoods all the time," Basara said in an interview last week. "Every time we're out there, it's, 'When are they coming down? When are they coming down?' They can't wait."

But once the worst of the vacant properties are gone, addressing the blight that mars each of the city's neighborhoods will become more complicated.

A survey by the nonprofit group CamConnect identified 3,417 deserted structures - close to 15 percent of the nine-square-mile city's buildings. Include the city's 8,000-odd vacant lots, and about 37 percent of the city's land is empty, according to CamConnect. That's far too much for the city to be able to redevelop or demolish, CamConnect program manager Josh Wheeling said. And, unlike Louis Street, some of the city's abandoned properties sit between well-maintained homes.

"People think we can just bulldoze whole blocks," Camden County spokesman Dan Keashen said in a recent interview. "It's not that easy."

For the first time, however, officials have a comprehensive map of the city's properties. Volunteers and members of CamConnect and the Camden Community Development Association spent two years surveying Camden on foot, block by block, comparing their findings to public records and compiling the data in an online map that allows users to view tax and ownership information for buildings across the city.

Wheeling, who presented the findings in a meeting this month with community leaders and city residents, hopes making the records accessible will encourage leaders to use the data to shape their future plans.

"Until you really know the extent of the problem, you're limited in the changes you can make," he said.

Confusion has historically attended Camden's dilapidated buildings, which often have incomplete records in terms of ownership, occupancy, and tax history. Many were abandoned long ago by owners who walked away; others were left in limbo when out-of-state owners died without transferring deeds. Some houses are classified as abandoned because mail carriers report no one accepts mail there, Wheeling said, and some are reported abandoned by owners who don't want to pay taxes. Others have become shelters for squatters.

Previously, the city razed buildings when acting on recommendations from the code enforcement department, and it did not keep a full list of abandoned properties until after 2008, when Mayor Dana L. Redd took office. Camden has demolished 464 abandoned properties in the last several years and boarded up more than 2,200, according to the Mayor's Office.

But since Camden County took over the city police department last year and increased walking patrols, the presence of officers in some neighborhoods has forced more crime indoors, officials said. Close to half the city's homicides this year were committed inside, Police Chief Scott Thomson said, with shootings on the street down 47 percent since 2012.

In October, the city launched its plan to raze 62 buildings, mostly in Whitman Park, followed by 534 others. City workers are shutting off utilities and preparing the first group for teardown, Basara said. The city hopes to finish the demolitions within 18 months.

The contract for the first job was awarded last month to Tricon Enterprises, a New Jersey company that will get $949,000 from a federal Community Development Block Grant. The second, $8 million citywide phase, which the city expects to put out to bid in the coming months, will be financed by a bond to be paid off with revenue from a tax on city parking lots.

Community members have expressed cautious optimism, though many say they have felt excluded from discussions of how to best tackle blight in their neighborhoods. At a meeting this month at Rutgers University in Camden at which Wheeling presented his group's data, activist Kristen Nalen of the group Camden Churches Organized for People questioned whether the city could do more to help potential homebuyers rehab abandoned properties.

"We know residents who talk about wanting them," she said. "Is there a tool to release these properties?"

Basara said the city hoped to save properties when possible. Demolition costs as much as $25,000 per house and leaves a vacant lot. Developers and residents may be interested in buying specific houses, or in turning vacant lots into community gardens.

But that's easier said than done.

In addition to the CamConnect map, anyone interested in owning one of the city's empty houses can seek information via City Hall's online database of abandoned properties. Anyone can submit plans for a particular project, Basara said, and if the proposal makes sense, the city will work to get the property into the applicant's hands, whether that means seizing it by eminent domain or acquiring it from an owner. The applicant would be required to pay only the legal fees for the city to transfer the deed.

It can take anywhere from a couple of months to a couple of years to finalize such a transaction, depending on circumstances, Basara said. He said the city had completed more than 100 such transactions in recent years and hoped to see that number grow as city officials learn ways to streamline the system.

"It's a challenge, but we're trying to take a comprehensive approach to neighborhoods," he said. "We know there is a market out there for housing in the city. Getting the right properties in the hands of the right people, that just takes time."