Crime and safety are top criteria to consider when choosing a place to live or travel. The Federal Bureau of Investigation (FBI) provides Unified Crime Reporting data that identifies crimes and indicates a city or police department where each crime occurred. Crime data may also be obtained from police departments and other agencies. Some of the crime data includes latitude and longitude that specifies a geographic coordinate of a point on the Earth's surface where the crime occurred. The crime data may be displayed on a map that has darker shading in areas having more reported crimes and lighter shading in areas having less reported crime. However, this mapping of crime data may be misleading. In addition, the mapping does not provide the information needed to make an accurate assessment of one's safety in a specific area.
Some organizations have created statistical models to predict crime rates or trends. However, the statistical models are prone to errors, such as statistical errors and incorrect modeling assumptions or techniques. For example, a statistical model may predict more crime in poor neighborhoods, but this prediction may not account for factors that discourage crimes, such as a cohesive community focused on crime prevention, an organized neighborhood watch program, or vigilant enforcement by police in the neighborhood.
Embodiments of the disclosure are directed towards a crime assessment tool and method for comparing and visualizing crime statistics in a manner such that an accurate assessment of safety in one area may be compared to the safety in another area. The crime statistics may be normalized based on a population basis and/or on crime severity. The areas for comparison may be specified at various levels, such as cities, neighborhoods, specific addresses, or the like. Trending information may be visually provided to aid in assessing the safety of different areas.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
The following disclosure describes a crime assessment tool and method for comparing and visualizing crime statistics in a manner such that an accurate assessment of safety in one area may be compared to the safety in another area. The crime assessment tool takes into consideration that more crime may occur where there are more people by determining a per capita crime rate. Furthermore, the crime assessment tool considers the severity of the crime by applying different weights to different types of crime to obtain a weighted per capita crime rate for specified areas. The areas for comparison may be specified at various levels, such as cities, neighborhoods, specific addresses, or the like. The crime assessment tool determines a crime indicator, such as a score, a ranking, a letter grade, a percentile, or the like. The crime indicator may be used to compare different areas with each other. The crime assessment tool may use geotagged crime data and thus, provide a more accurate depiction of crime statistics than predictive statistical models. In addition, the crime assessment tool may provide useful trending information to aid in visually assessing the safety of different areas over a period of time.
System 100 includes a crime assessment tool 102, one or more crime data sources 104, one or more sources to estimate people present in an area 106, an area selection input 108, and crime weights 110. The crime data sources 104 include crime data from police departments, crime data from third parties via application programming interfaces (APIs) or other web services. Crime data may be imported as various data formats, such as a CSV or JSON file. Some cities provide public access to some or all of their crime report data. While cities may record crime incidents using different fields of data, the crime assessment tool can interpret the different fields to generate useful statistics. In addition to the above mentioned sources, crime data sources 104 may include more timely crime data such as crime data imported by crawling or scraping websites or social media. For example, many cities have crime blotter services—either official, run by news outlets, or private citizens—that report on crimes shortly after incidents occur, or in some instances as the incident is occurring. Some of the crime blotter services may be available as a Really Simple Syndication (RSS) feed that can be easily imported into the crime assessment tool 102. For other crime blotters, the information may be imported using other techniques, such as a commonly known technique of web scraping. Typically, the information obtained from blotters may be more timely than other data sources, but may be less comprehensive than the crime data obtained from other data sources, such as police departments. Crime data sources 104 may also include 911 call data, which can be imported using a process similar to importing crime incident reports from police departments. The system may also allow collection of crime incidents from users.
The sources to estimate people present in an area 106 may include census data, employment statistics, cell phone usage data, social media data, and the like. One set of census data may provide the number of residents living in an area. However, this set of census data alone may not accurately reflect the people present in the area at different time periods. For example, some downtowns have a small number of residents, but have a large day time population from all the employees who work downtown. Thus, the sources 106 may also include databases of jobs from various sources, such as the Longitudinal Employer-Household Dynamics database from the United States census. Some of the sources 106 may be geocoded so that the data may be analyzed spatially. However, if the sources 106 are not geocoded, the crime assessment tool 102 may be configured to estimate the number of employees and residents in a specified area to obtain the people present in the area for the specified time period. The sources 106 may also include population analytics based on anonymous cell phone data, social signals (e.g., a number of unique tweets occurring in an area), sensors, or the like. For example, a sensor may count pedestrians and this count of pedestrians may be used to further enhance estimates of how many people are actually present in the area. In some embodiments, the information from the sources 106 is input into the crime assessment tool 102 offline, but the information may also be continually updated if so desired.
The area selection 108 provides an area to the crime assessment tool 102 which then may assess the safety of the provided area. The area selection 108 includes techniques for determining a geometry or shape around an address to be analyzed. In some embodiments, the area selection may include commonly available boundary shapefiles, which are datafiles that store information about a geographical or geometrical shape. Shapefiles, for example, are commonly used in the real estate industry and are often made available by city governments. The shapefiles are used to store the boundary shape of neighborhoods. In other embodiments, tthe geometry or shape may be determined using a “walk shed,” which is an area around the address that is walkable in a specified amount of time. The technique described in United States Application No. 2013/0046795 may be used to determine the “walk shed” and is hereby incorporated by reference in its entirety. Using a “walk shed” to analyze nearby crimes provides an accurate way to determine which crimes are likely to affect an address (e.g., a home). For example, crimes on one side of a busy freeway are less likely to affect the quality of life of residents living on the other side of the freeway. The walk shed may be based on any interval of time and the area determined by the walk shed is determined to be the area from which a person can walk from a specified address in any direction for the specified interval of time (e.g., 15 minutes). The end points in each direction define an outer boundary for the walk shed.
Crime weights 110 may be supplied. In some embodiments, the weight of a crime may depend on the severity of the crime. For example, a minor property crime such as a broken car window may have a lower weight than an armed robbery of a home. Weights based on the severity of violent crimes may be applied correspondingly. For example, a murder may have a higher weight than an assault. Crimes that are not location based (e.g., fraud) may be given a weight of zero, thereby excluding the crime in the assessment for the area. In addition, some crimes may have a different weight in each of the categories of crimes in which the crime is categorized. For example, an armed robbery of a house may have the same or different weight for both a violent crime and a property crime category.
The crime assessment tool 102 may include a crime data categorization component 120, a crime rate component 122, a people estimation component 124, a crime rate processing component 126, a crime indicator component 128, a user feedback component 130, and an output component 132. The crime data categorization component 120 receives the crime data from the crime data sources 104. The fields of interest in the crime data include time, location, and category of the incident. The crime data sources 104 may report the crime data using different fields and in addition, different cities may categorize crimes differently. For example, the city of Seattle currently has 190 unique categories of crime, while the city of Houston currently has eight unique categories. The crime data categorization component 120 may translate these different classification schemes into a single categorization system. In addition, the crime data categorization component 120 may translate location information into a consistent format for use by the crime assessment tool 102. In some embodiments, different representations may be translated into latitude and longitude coordinates. If block-level addresses are provided, the crime assessment tool 102 may employ a third party service to translate the block-level addresses to obtain latitude and longitude coordinates using a process called geocoding. If x,y coordinates are used to specify the crime location, the crime data categorization component 120 may translate the x,y coordinates using details about the projection used in determining the x,y coordinates.
The crime data categorization component 120 may categorize crimes in various ways. In some embodiments, crime may be categorized as a property crime or a violent crime. In other embodiments, crime may be categorized by a level of severity. In other embodiments, crime may be categorized as a personal crime or a property crime. It will be appreciated that in addition to the above-mentioned schemes, combinations of the above schemes and other categorization schemes may be used by the crime assessment tool 102. The inventors of the present crime assessment tool 102 have discovered that by weighting crimes by severity, the crime assessment tool 102 can more accurately assess crime statistics and decrease noise. For example, while property crimes occur everywhere, applying the same weight to graffiti as to a home burglary results in a less accurate assessment of the risk to personal property. In addition, by weighting crimes by severity, the crime assessment tool can achieve more accurate comparisons between neighborhoods. In one embodiment, severe crimes may be weighted with a value of 1, less severe crimes may be weighted with a value of 0.25, and crimes that are not location specific or crimes that do not result in any impact to the quality life may be given a value of 0. As briefly discussed above and discussed further in conjunction with
Crime rate component 122 determines a weighted crime rate for an area in question. The area being considered may be input from the area selection 108, such as a shapefile or walk shed. The process for determining the weighted crime rate is illustrated in
People estimation component 124 estimates the number of people that are present in the area at a specified time. Estimates of the people present may be created at various times of the day. For example, a daytime estimate may include the working population during working hours and subtract out the number of residents who commute away from the area. The people estimation component may estimate the people present by using anonymous cell phone location data to predict or analyze the estimate on an hourly basis. For example, available services may be used to estimate the people present in an area at a specified time using anonymous cell phone data.
Crime rate processing component 126 determines a weighted per capita crime rate in an area. The weighted per capita crime rate is determined by dividing the total weighted crime rate in an area by the estimate of people present in the area for a specified time period. The weighted per capita crime rate may be determined for different crime categories, such as determining the weighted per capita crime rate for violent crimes and property crimes, separately. In addition, the weighted per capita crime rate may be determined for different periods of time, such as daytime hours versus nighttime hours. Determining weighted per capita crime rate using different time periods may be useful in indicating differences in crime rates that are dependent on different types of crimes. For example, having daytime and nighttime periods may help indicate whether a neighborhood is unsafe during the day, during night, or both. By assigning a value to each time period, crime statistics may be used to compare daytime and nighttime safety between neighborhoods or cities. Using time periods aids in comparisons since some crowded area (e.g., a downtown tourist attraction) may be safe during the day when there are more people, but may be unsafe at night when there are fewer people. It can be appreciated that any number of additional time periods may be used in determining crime statistics per capita. For example, time periods may be computed on a monthly or seasonal basis to identify particular times of the year that are safer or less safe than other times of the year in a given neighborhood, city, or geographic area, thereby providing trending information.
Crime indicator component 128 is configured to create a rating indicator for specified areas. Because it is often difficult for individuals to compare crime rates since crime rates are typically reported in incidents per thousand people, crime indicator component 128 may normalize the crime rates into a rating indicator. The crime indicator component 128 may base the rating indicator on individual addresses, neighborhoods, cities, national statistics, or the like depending on a desired comparison. In addition, the crime indicator component 128 may normalize the rating indicator to further refine the safety assessment calculated for specified areas and aid in presenting helpful visual representations of the safety assessment.
User feedback component 130 accepts input from a user of the crime assessment tool and incorporates the feedback into the crime assessment. Oftentimes, the perception of whether an area is safe is a meaningful factor on whether people actually feel safe in an area. The user feedback component 130 collects feedback from users. The crime assessment tool 102 may be provided as a network accessible application, such as a web page specified by a Uniform Resource Identifier (“URI”) and displayable via a web browser, or, may be provided via a server or as a web service and integrated into another, perhaps third party, application. The user feedback component 130 may use any conventional method for inputting data.
Output component 132 provides visual displays for easily assessing the safety of specified area. It will be appreciated that various visual representations, such as a ranking, a letter grade, a percentage, a numerical representation (e.g., a score), symbolic representations (e.g., a star rating system), a graphic/iconic/symbolic representation (e.g., a map with icons), or the like may be output. Several of these various visual representations are illustrated in
Output component 132 may also provide a display in which crime trends are illustrated over time for a specified area (e.g., city, neighborhood, address). The display of the crime trends may, for example, provide insight into questions regarding safety during the summer when students are not at school, safety in correlation with weather, safety in correlation with the economy in an area, and the like.
At block 204, the crime assessment tool projects a shape of the area onto a plane to produce a geometry G. At block 206, the crime assessment tool analyzes the crime reports in the database to determine a location associated with the crime report. At block 210, a point p is computed by projecting latitude and longitudinal coordinates of the crime. In some embodiments, the location may be specified using latitude and longitudinal coordinates in a manner that the location identifies point p. In other embodiments, once an area is determined for analyzing crime statistics, standard geospatial techniques may be implemented to determine which crimes occurred within the boundary of the area. At block 212, if a point p lies within geometry G, the weight of the associated crime is added to a total weight (TW) that represents the weighted crime rate for an area. One will appreciate that multiple weighted crime rates may be calculated using process 200 separately or concurrently. One exemplary illustration of a weighting scheme is illustrated in
At block 302, the crime assessment tool calculates the residents in the area based on census blocks. At block 320, for each census block intersecting the area, the crime assessment tool performs blocks 322, 324, and 326. If the census block does not intersect the area, the census block may be ignored. At block 322, the crime assessment tool calculates a percentage of the census block that intersects the area. At block 324, the calculated percentage is multiplied by the total residents identified for that census block to obtain a partial resident count associated with the census block. At block 326, the partial resident count for the census block is added to a running total of partial resident counts from each of the intersecting census blocks. After all of the census blocks that intersect with the area have been processed, the sum of all the partial resident counts yields the estimated total number of residents in the area. In some embodiments, as a further refinement, a number of residents that commute out of the area for the specified time period may be determined and subtracted from the estimated total number of residents to yield a new estimated total of residents in the area.
At block 304, the crime assessment tool calculates the employees in the area. At block 330, for each census block intersecting the area, the crime assessment tool performs blocks 332, 334, and 336. If the census block does not intersect the area, the census block may be ignored. At block 332, the crime assessment tool calculates a percentage of the census block that intersects the area. One will appreciate that this percentage may yield the same percentage as block 332 if the same census block provides both resident information and employee information. For this embodiment, the percentage calculated for block 322 may used without re-calculating the percentage in block 332, if so desired. At block 334, the calculated percentage is multiplied by the total number of employees identified for that census block to obtain a partial employee count for the census block. One will appreciate that the number of employees may be based on the number of jobs identified for the census block. At block 336, the partial employee count for the census block is added to a running total of partial employee counts from each of the intersecting census blocks. After all of the census blocks that intersect with the area have been processed, the sum of all the partial employee counts yields the estimated total number of employees in the area. In a further refinement, unemployment data, job openings, or other job related data may be reflected in the total number of employees in the area by adjusting the partial employee count for each block, adjusting the total number of employees, or the like.
At block 306, the total number of residents from block 302 is summed with the total employees from block 304 to yield an estimate for the number of people present in the area for a specified time period.
At block 308, additional analytics may be applied to adjust the estimated number of people present. The crime assessment tool may optionally employ population analytics based on anonymous cell phone data, social signals (e.g., a number of unique tweets occurring in an area), sensors, or the like. For example, a sensor may count pedestrians and this count of pedestrians may be used to further enhance estimates of how many people are actually present in the area at a specified time period.
At block 310, the weighted crime rate for the area is obtained as determined during processing in
At block 312, the weighted crime rate is divided by the estimated number of people present in the area to yield the weighted per capita crime rate for the area. The weighted per capita crime rate for different area calculations may then be used to visually represent a safety assessment for areas of interest.
While the above visual representations for displaying various rating indicators are helpful in comparing safety between different addresses, neighborhoods, cities, and the like, the rating indicators do not provide information for users to understand the safety of each area based on the actual crime rates, but rather comparisons with other areas. For example, in
At block 804, the crime assessment tool determines saturation values. The saturation values include a minimum saturation value and a maximum saturation value. The minimum saturation value and the maximum saturation value are constants that define values, relative to an average crime rate, that are used to obtain a score of 0 or 100, respectively. By implementing saturation values, the crime assessment tool handles situations where a city may not have a high crime neighborhood.
At block 806, the crime assessment tool sets a crime rate. When the normalization is based on a city level, the crime rate is set to reflect a city rate. In some embodiments, the crime rate is set to 50 when the normalization is based on a city level. The crime rate provides a metric for comparing neighborhoods in a city to one another. Because some neighborhoods are less safe than the city's general safety and some neighborhoods are more safe than the city's general safety, the crime rate is set as a pivot point to divide the two classes of neighborhoods. The crime rate may be set an any arbitrary value. In some embodiments, the crime rate is set at or near the middle, such as 50 for a range between 0 to 100.
At block 808, the crime assessment tool obtains a neighborhood rate for evaluation. The neighborhood rate may be obtained using process 300 illustrated in
The neighborhood rate corresponds to the weighted per capita rate calculated for the specified area (i.e., neighborhood).
At block 810, the crime assessment tool determines a difference based on the neighborhood rate and the crime rate. In some embodiments, the difference may be determined by dividing the neighborhood rate by the crime rate and subtracting a value, such as 1, thereby grouping the neighborhood being evaluated into one of the two general classes: the more safe neighborhood class or the less safe neighborhood class.
At block 812, the crime assessment tool determines a crime score for the neighborhood based on the saturation values and on the difference. In overview, the crime score provides a rating indicator that normalizes crime rates in a manner that allows different neighborhoods in the same city or different cities to be compared with one another. The crime score takes into account that some cities may not have high crime neighborhoods. Table 4 illustrates exemplary pseudocode determining a crime score for neighborhoods in a city.
In some embodiments, the min saturation is set to −1 and the max saturation is set to 1. With these settings, a neighborhood with a crime rate of at most 100% less than the city rate (i.e., no crime) is assigned a crime score of 0 and a neighborhood with at least 100% higher crime rate than the city rate is assigned a score of 100.
The process 800 illustrated in
The processor unit 1202 is coupled to the memory 1204, which is advantageously implemented as RAM memory holding software instructions that are executed by the processor unit 1202. These software instructions represent computer-readable instructions and computer executable instructions. In this embodiment, the software instructions stored in the memory 1204 include components (i.e., computer-readable components) for a crime assessment tool 1220, a runtime environment or operating system 1222, and one or more other applications 1224. The memory 1204 may be on-board RAM, or the processor unit 1202 and the memory 1204 could collectively reside in an ASIC. In an alternate embodiment, the memory 1204 could be composed of firmware or flash memory.
The storage medium 1206 may be implemented as any nonvolatile memory, such as ROM memory, flash memory, or a magnetic disk drive, just to name a few. The storage medium 1206 could also be implemented as a combination of those or other technologies, such as a magnetic disk drive with cache (RAM) memory, or the like. In this particular embodiment, the storage medium 1206 is used to store data during periods when the computing device 1200 is powered off or without power. The storage medium 1206 could be used to store crime rates, crime scores, weights, trend data, and the like. It will be appreciated that the functional components may reside on a computer-readable medium and have computer-executable instructions for performing the acts and/or events of the various method of the claimed subject matter. The storage medium being on example of computer-readable medium.
The computing device 1200 also includes a communications module 1226 that enables bi-directional communication between the computing device 1200 and one or more other computing devices. The communications module 1226 may include components to enable RF or other wireless communications, such as a cellular telephone network, Bluetooth connection, wireless local area network, or perhaps a wireless wide area network. Alternatively, the communications module 1226 may include components to enable land line or hard wired network communications, such as an Ethernet connection, RJ-11 connection, universal serial bus connection, IEEE 1394 (Firewire) connection, or the like. These are intended as non-exhaustive lists and many other alternatives are possible.
The audio unit 1228 may be a component of the computing device 1200 that is configured to convert signals between analog and digital format. The audio unit 1228 is used by the computing device 1200 to output sound using a speaker 1230 and to receive input signals from a microphone 1232. The speaker 1232 could also be used to announce incoming calls.
A display 1210 is used to output data or information in a graphical form. The display could be any form of display technology, such as LCD, LED, OLED, or the like. The input mechanism 1208 includes keypad-style input mechanism and other commonly known input mechanisms. Alternatively, the input mechanism 1208 could be incorporated with the display 1210, such as the case with a touch-sensitive display device. Other alternatives too numerous to mention are also possible.
While the foregoing written description of the invention enables one of ordinary skill to make and use a crime assessment tool as described above, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the described embodiments, methods, and examples herein. In addition, those skilled in the art will appreciate that the crime assessment tool may be used for providing safety assessments for real estate services, travel and vacation services, urban planning, and others. Thus, the invention as claimed should therefore not be limited by the above described embodiments, methods, and examples, but by all embodiments and methods within the scope and spirit of the claimed invention.
This application claims priority under 35 U.S.C. Section 119(e) to U.S. Provisional Application Ser. No. 61/847,848 filed Jul. 18, 2013 entitled “System and Method for Comparing and Visualizing Crime Statistics” the disclosure of which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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61847848 | Jul 2013 | US |