Who owns vacant properties in Baltimore?

I received many ideas for my free software project and ultimately settled on one suggested by Kate Bladow: a tool to help identify potential slumlords in Baltimore. It's specifically designed to help Baltimore Slumlord Watch investigations, though that anonymous blogger has nothing to do with this tool (he or she has to do complete investigations of each property before writing a post). This is more like an experiment to use all available data to identify people and companies who may own a large number of vacant properties.

The tool combines data from three sources:

1. State of Maryland Real Property database: to get a complete list of every property in Baltimore, identified by a block and lot number (this database, unlike #2, allows wildcard searching, which is how we get the complete list). Includes a truncated field listing the owner name.
2. Baltimore City Real Property database: to find the complete owner name and mailing address.
3. Baltimore's Vacant Lots and Vacant Buildings open data sets. The anonymous slumlord watch blogger says that these are not very accurate or up-to-date, but hopefully they are good enough for us to identify who the main offenders are.

I applied a few cleanups and transformations to make the data more useful, and used the excellent Google Refine tool to try and reduce the noise I found in the Owner Name column. Many entities were listed under a variety of spellings, punctuations, and abbreviations, which Google Refine helped me combine. Thanks to Mark Headd for recommending Google Refine to me.

Below you will find a few lists of the top property owners in Baltimore gleaned from these tools.

Important Caveats

1. Some properties are owned by companies using a series of one-up numbered company names (like "N# Inc." or "NB1 Business Trust", "NB2 Business Trust", etc.  I used Google Refine's clustering feature to combine similar names on the assumption that these are probably controlled by the same people. In the cases where I did this kind of grouping, I used sentence case instead of upper case or I replaced digits with the # sign.
2. Many properties are owned by a uniquely-named LLC (like "1 E. Montgomery LLC"). One person or company could own a significant share of the vacant properties in Baltimore via shell corporations like this. One potential way to get around this is to look up the incorporation paperwork for each company (also available as a scrapeable database), but I'm assuming if you're smart enough to use shell corporations you're probably using a different company to be a registered agent. So this technique would probably only help us identify the main registered agents for the vacant property owners in Baltimore.
3. I haven't done a great deal of authenticating or verifying. All I'm trying to do is make this data more discoverable/explorable. Obviously you should do your own homework before acting on any of this information.
4. I was really surprised to see how much property is controlled by the city. Even if the absolute numbers below are inaccurate the relative amount is pretty amazing. I'd like to see the city take some bold leadership on doing something with all of those buildings and lots. How about a revival of the dollar home program?
5. I only focused on properties listed as non-owner occupied by the State of Maryland.
6. The Slumlord Watch blogger says that the city's vacant building data is inaccurate and not up-to-date, so there may be false positives and negatives in the list.

Largest Vacant Property Owners in Baltimore, Grouped by Name

Owner	#  Vacants
Baltimore City	1407
UP# BUSINESS TRUST	38
SS# BUSINESS TRUST	25
JAMES E. CANN	24
NB# Business Trust	24
State of Maryland	19
2008 DRR-ETS, LLC	18
BALTIMORE RETURN FUND, LLC	18
EAST BALTIMORE DEVELOPMENT LLC	18
COMPOUND YIELD PLAY, LLC	17
CE REALTY, LLC. & EPHRAIM WEINGARTEN	16
KONA PROPERTIES, LLC	16
CE REALTY, LLC	15
J.A.M. numbered corporations	15
BALTIMORE PREFERRED PROPERTIES LLC	14
DRUID HEIGHTS COMMUNITY DEVELOPMENT CORPORATION	14
HOLABIRD INVESTMENTS, LLC	14
NEW HORIZON DEVELOPMENT, LLC	14
DOMINION PROPERTIES LLC	13
COMMUNITY SOLUTIONS, LLC	12
M&S JOINT VENTURE DEVELOPMENT CORPORATION	12
MAHS-BE HOLDINGS, LLC	12
BALDWIN TRUSTEE, LEROY	11
HARRISON DEVELOPMENT, LLC	11
HUD	11
CHESAPEAKE HABITAT FOR HUMANITY INC	10
KGB numbered corporations	10
University of Maryland	10
L.A.M.B., INC.	9
REBUILD AMERICA, INC	9
CARTER, NATHAN	8
EQUITY TRUST COMPANY	8
KREISLER, SANFORD	8
LAMB, DERRICK	8
N-#, INC.	8
OAKMONT DESIGN LLC	8
SANDTOWN HABITAT FOR HUMANITY	8
DOMINION RENTALS, LLC	7
GREEN, CARL	7
HARBOUR PORTFOLIO	7
LEO, CAROLINE G.	7
N10 BUSINESS TRUST	7
NEIGHBORHOOD PROPERTIES-4, INC	7
SAUNDERS TERRAINE	7
EAST BALTIMORE DEVELOPMENT, INC	6
APP CONSULTING GROUP, LLC	6
DJ LAND CO, LLC & WODA GROUP LLC	6
EMERALD BAY DEVELOPMENT GROUP & ONE, INC.	6
FIRST NATIONAL DEVELOPMENT, LLC	6
JOHNSON, MARTIN	6

You can also download the entire list of non-owner-occupied vacant building owners in Baltimore.

Largest Vacant Lot Owners in Baltimore, Grouped by Name

Baltimore City	2926
B&D PHASE III, LLC	64
METRO II OLDHAM, LLC & SUNNYS ASSOCIATES, LLC	42
CAMDEN ASSOCIATES, LLC.	40
HARBORVIEW LIMITED PARTNERSHIP NO. #	35
State of Maryland	32
LOWMAN ST.,LLC	31
Oblate Sisters of Providence	27
BG&E	23
COMPANY, LLC & FEDERAL HILL HOLDING & SCC CANYON II, LLC	23
ATLAS MD I SPE, LLC & BB&T BANK (CREO), ATTN: T. GEORG	19
J & J PARTNERSHIP, INC.	19
Baptist Church	18
SANDTOWN HABITAT FOR HUMANITY	18
NANTICOKE INVESTMENT CO., LLC	17
L.A.M.B., INC.	15
CSX TRANSPORTATION, INC. & TAX DEPARTMENT	13
DRUID HEIGHTS COMMUNITY DEVELOPMENT CORPORATION	13
SINGER PARK & PLAY, INCORPORATED	13
STATION PLACE LLC	13
TRIMARK MANAGEMENT	13
ASSOCIATION, INC & MCHENRY POINTE HOMEOWNERS	12
Benedictine Society of Baltimore	12
CHESAPEAKE HABITAT FOR HUMANITY & INC	12
JUBB JR, WALTER H & JUBB, EDWARD H	12
CASTLEWOOD COMMUNITIES, LLC	11
MOUNT SINAI BAPTIST CHURCH & OF BALTIMORE CITY	11
MARYLAND JOCKEY CL	10
CONVENTION AND AUXILIARIES & OF BALTIMORE, INC. & UNITED BAPTIST MISSIONARY	9
DUNN, GREG	9
RIVERSIDE WORK FORCE LLC	9
BALTIMORE URBAN LEAGUE, & INC.,THE	8
C&P TELEPHONE COMP	8
CORPORATE SECRETARY, AMTRAK & NATIONAL RAILROAD & PASSENGER CORPORATION	8
DEVELOPMENT CORPORATION & DRUID HEIGHTS COMMUNITY & JACQUELYN D CORNISH	8
FRP HOLLANDER 95, LLC	8
HOLABIRD PARK APTS. INC	8
MUELLER HOMES, INC.	8
NEWSTAR DEVELOPMENT AT CANTON & PEAKS, LLC	8
SCARFIELD SR, FRANK D	8
THE KCR DEVELOPMENT GROUP & SPICER'S RUN HOMEOWNER ASSOCIATION
BALTIMORE SCRAP CORP.	7
BRIGHTON DEVELOPMENT GROUP & LLC	7
CHURCH, THE & VESTRY OF MOUNT CALVARY	7
FLAG HOUSE RENTAL I, L.P. & METRO PLAZA II	7
FOWLKES, ROBIN	7
PARADIGM BUILDERS, LLC & RICHARD MIRSKY - OFFIT KURMAN	7
URBAN HEALTH INSTITUTE OF & WASHINGTON, THE	7
CANN JAMES E	6
CHURCH OF THE REDEEMED OF THE & LORD, INC, THE	6

You can also download the entire list of non-owner-occupied vacant lot owners in Baltimore.

The Raw Data
All data used to create the above table can be downloaded from Github, including the raw CSV data.

The Code

It's creative-commons licensed and posted on Github. It's pretty raw and unfactored. I ran it all from irb. It needs to be converted into a Rake task or other command-line friendly, totally-automated package.

Next Steps

• We could get this up and running on ScraperWiki to have the data constantly updated.
• We could run an Amazon Mechanical Turk project to create an up-to-the-minute database of vacant houses in Baltimore, using Google Street View. We could just ask each worker to use street view to make an estimate of whether the house was vacant or not. I'm sure there would be some inaccuracy but the data ought to be good enough to help further investigations.