Title

Density of Sex Offenders Surrounding Schools in Neighborhoods of Varying Income Level in Sacramento County

Author

Florence Surratt

American River College, Geography 350: Data Acquisition in GIS; Spring 2008

Contact Information: fesurratt@yahoo.com

 

Abstract

To show whether or not schools in lower income neighborhoods have a higher density of sex offenders nearby than schools in higher income neighborhoods.

 

Introduction

Initially, for my project, I wanted to do something where I analyzed the number of sex offenders in the neighborhood surrounding my children’s school. However, when I went to the Megan’s Law website and did a search on their school, I found that there were very few offenders in the area. While this was good news to me as far as the school is concerned, it didn’t give me a very interesting project. In trying to figure out how to use this information, I realized that I live in an upper-middle class, suburban neighborhood and perhaps that was the reason for the low density of sex offenders. This led me to my final project idea to analyze whether or not the income level of the neighborhood in where a school is has any affect on the density of surrounding sex offenders. I also chose to change my focus to Sacramento County, although I live in Placer County, because there is a wider range of variables there. You have the urban center around Downtown Sacramento to the rural areas in the southern part of the county to the suburbs in the northern and eastern parts.

 

Background

For more than 50 years, California has required sex offenders to register with their local law enforcement agencies. However, information on the whereabouts of these sex offenders was not available to the public until the implementation of the Child Molester Identification Line in July 1995. The information available was further expanded by California’s Megan’s Law in 1996 (Chapter 908, Stats. of 1996). This information was available only by personally visiting police stations and sheriff offices or by calling a 900 toll-number.

A new law that passed in 2004 provided the public with internet access to detailed information on registered sex offenders. This expanded access allows the public to use their personal computers to view information on sex offenders required to register with local law enforcement under California’s Megan’s Law.

The search engine of the website allows searches by name, address, city, ZIP code, county, schools and parks. Once you get your search result window, you can click on the blue boxes (the offenders’ locations) and you get another screen that will give you a picture, physical description, address and the offense(s) for that particular offender.

 

 

 

 

 

 

California’s Megan’s Law provides the public with certain information on the whereabouts of sex offenders so that members of our local communities may protect themselves and their children. Megan’s Law is named after seven-year-old Megan Kanka, a New Jersey girl who was raped and killed by a known child molester who had moved across the street from the family without their knowledge. In the wake of the tragedy, the Kankas sought to have local communities warned about sex offenders in the area. All states now have a form of Megan’s Law.

California was the first state in the nation to enact a sex offender registration law. Many states did not enact sex offender registration laws until the 1990’s. Due to its lifetime sex offender registration requirement and a population exceeding an estimated 35 million residents, California today has the largest number of registered sex offenders of any state.

The law is not intended to punish the offender and specifically prohibits using the information to harass or commit any crime against an offender.

 

Methods

My first decision was to determine which geographic area to cover. As stated in my introduction, I ultimately decided on Sacramento County because it is relatively local, yet has a more diverse economic population than Placer County.

I then decided to limit my study to public, elementary schools. I chose that because that is the type of school that my children attend. Also, I feel that younger children are more susceptible to “stranger danger,” i.e.: more likely to fall for the “I lost my dog. I’ll give you candy if you help me look for him” trick than say a high schooler would.

Finally, I had to decide what kind of census data to use to determine income level. I was originally going to use median household income, but realized that a single person making $50,000 annually is in a different category than a family of 5 with the same income. Therefore, I ultimately decided to go with per capita income.

After I made these initial decisions, the next step was to actually find the data sets that I needed. The first step was to locate the census data. I had a little bit of trouble finding the files in the correct format but I ultimately found what I needed at http://factfinder. census.gov. Here I was able to download a table of all the census tracts with the annual per capita income.

The next step was downloading a shapefile of the Sacramento County census tracts. I found the TIGER files I needed at the census website, http://www.census.gov. After downloading these two files and adding them to my ArcMap file, I was able to join the tables so that I could symbolize the census tracts based on the income information. I chose to classify using three classes and the natural breaks method in order to come up with low, middle and high income neighborhoods.

Now that I had set up the general geography, the next step was to add point files of the schools and sex offenders. Finding the data for the Sacramento County schools proved to be challenging. Most of the school district websites would list all the schools, but then you’d have to follow a link to get the address. This would prove to be too time consuming for the nearly 175 schools. I was able to find a website, http://www.greatschools.com, where you can search schools by district (or other parameters) and apply further filters to narrow your search. So I entered each district individually and filtered to public and elementary schools. My search came up with a list of schools that included the addresses, so I was able to copy and paste into a MS Word file, do a little editing, and finally import all the data into an MS Excel file that could then be imported into my ArcMap file.

I was then able to geocode the schools against the street centerline file I found for Sacramento County at http://www.msa.saccounty.net. Once geocoded, I selected a sample of schools to use for my study. I chose a number of schools in each economic region. Additionally, I tried to choose schools that weren’t too close to each other so there’d be as little overlap as possible in nearby offenders. I chose schools in areas of various population densities, and also schools that I thought would be of particular interest, such as one school in a small pocket of a high income neighborhood that was surrounded completely by middle and even one low income tract.

 

 

 

 

Once I chose the schools to analyze, I needed to collect the sex offenders’ information. Using California’s Megan’s Law website (http://www.meganslaw.ca.gov) I was able to search by school. I decided to use a 3/4 mile radius for my search. A radius of 1 mile returned far too many offenders in the lower income areas and the 1/10 of a mile radius too few in the higher income neighborhoods. I copied and pasted each address into an MS Excel table and also included a field for the school that the offender is near. When I completed this for each school, I added the table to my map document and geocoded the offenders’ addresses.

 

Results

After all the downloading, joining and geocoding, I ended up with a dot-density map showing my chosen schools and the nearby offenders.

 

 

 

This map does show the number of offenders around each school. However, because of the large size of the county and the small radius around each school, it is nearly impossible to enlarge it to a size where it can be more easily interpreted. Therefore, I created a summary table to show a more accurate count of offenders around each school. Also, the chart takes into account any offenders’ addresses that were unmatched in the geocoding process while the map does not.

 

 

 

Nearby

Income

School

Offenders

Level

H. W. Harkness

21

Low

Mark Twain

19

Low

Woodlake

16

Low

Coyle Avenue

14

Middle

Florin

13

Low

Frontier

12

Low

Glenwood

10

Low

Abraham Lincoln

9

Low

Rancho Cordova

8

Low

Hubert H. Bancroft

6

Middle

James R. Cowan

6

High

Valley Oaks

5

Low

Witter Ranch

5

High

Pony Express

4

Middle

Theodore Judah

4

High

Regency Park

3

Middle

Arcohe

2

Middle

Del Dayo

2

High

Barrett Ranch

1

Middle

Isleton

1

Middle

Raymond Case

1

Middle

Albert Schweitzer

1

High

Carl H. Sundahl

1

High

Pleasant Grove

1

High

Franklin

0

Middle

Genevieve Didion

0

High

Gold Ridge

0

High

Gold River Discovery Center

0

High

 

 

Analysis and Conclusion

I would say that in general, my findings are consistent with my hypothesis. They don’t show an absolute correlation, but definitely a general trend. For instance, James R. Cowan is a school in a high income level neighborhood that is relatively small and surrounded by middle and even one low income neighborhoods. In contrast, Valley Oaks is a low income school that is in a less densely populated tract. However, as you scan down the chart, you will see that the low income schools are clustered more towards the top, the middle income in the middle and the high income towards the bottom.

 

I did as much as I could to investigate my hypothesis, however, I was limited to the resources and time available to me. As a result of these limitations, there are several factors that could potentially change (or perhaps further strengthen) my findings:

1. Sample size

I only chose 28 out of over 175 schools. Would my findings be different if I had time to analyze a larger sample?

 

2. Outdated data

~The census data is from 2000, which makes it 8 years old. How has this information changed in that time and how could it possibly affect my results?

~All the Megan’s Law offender information comes with a disclaimer that the offender may have moved. Since an offender that moves has until 5 days after their birthdate to report their move, it’s possible that a number of offenders have moved either away from, or for that matter to, the school zones I analyzed. I also came across a handful of offenders that were tagged as being in violation of the registry.

 

3. Erroneous data from Megan’s Law

There were a few addresses that didn’t make sense, such as a single address reported to be in North Highlands when all surrounding offenders are listed as being in Sacramento.

 

4. Choice of buffer zone

If I had chosen a larger or smaller buffer zone, would that further confirm, or refute my hypothesis?

 

5. Some schools not mapped on Megan’s Law

A few of the schools that I had initially chosen came up with a “search not found” message at Megan’s Law. When I searched by address, a few were found, but still a couple were not so I had to swap out for another school.

 

6. Population density as a factor

From my dot-density map, it seems as if population density could possibly play a role in the density of sex offenders neighboring a school. It would take much more detailed analysis to determine whether income level or population density plays a greater role in my final findings.

 

References and Resources

www.census.gov

TIGER files for census tract and school district shapefiles

factfinder.census.gov

Census demographic information

www.meganslaw.ca.gov

Sex offender information

www.greatschools.com

Search engine for schools

www.msa.saccounty.net/gis/default.aspx

Sacramento County street centerlines