Mapping Low Level Marijuana Arrests

Jeff Reichman on in Data, Public Policy, Research

Update: February 20, 2017

Beginning March 1, 2017 marijuana will be effectively decriminalized in Harris County. The DA estimates this will save $25 million a year. Congratulations to DA Kim Ogg, Sheriff Ed Gonzalez, and everyone involved in this swift policy change.

Back in February 2016, Texas Lyceum published the results of a survey that found fewer than 20% of Texans believe that low level marijuana offenses should be criminal.

Currently, Texas law states that any possession of up to 2 ounces of marijuana is a Class B misdemeanor, punishable by up to 180 days in jail and a $2,000 fine.

But there are exemptions for marijuana Class B misdemeanors where an officer can write a citation in lieu of an arrest. In fact, Harris County District Attorney Devon Anderson made the First Chance marijuana diversion program a central part of her last campaign.

But data tells a different story. People are still arrested for small amounts of weed, at least by the Harris County Sheriff’s Office according to the Harris County Sheriff’s Office Justice Information Management system.

Between January 1, 2016 and June 30, 2016, I found 1,157 cases in Harris County where a Class B misdemeanor marijuana possession was the prompting charge for an arrest.

How I Made This Map

I put together a dataset of six months of arrest data compiled from publicly available, daily arrest records from the Harris County Justice Information Management System (JIMS). The data comes from 128 days of arrest records between January 1, 2016 to June 30, 2016. The missing days are the result of my script returning no response.

Next, I separated out the arrests where possession of 0-2 ounces of marijuana was the only Class B misdemeanor charge. Any arrest containing a charge above a class B misdemeanor was tossed out. I tried to create a dataset where the Class B possession charge was what prompted the arrest.

After adjusting the coordinates slightly for privacy, I mapped the home addresses of the people who were arrested. I obscured their exact address, and generalized the marker to span 300 meters. I believe this is true to the original data source without revealing personally identifying information.

Then I added a layer of median household income by census tract. By default, this overlay is turned off. You can turn it on by clicking on the box in the upper right hand corner of the map.

Once you turn on the Median Household Income layer, every tract that averages $80,000 or more in median household income is a shade of blue. The darker it gets, the higher the median household income for that census tract. Other census tracts are transparent, so you can click on any part of the map to pull up the median household income when this layer is on. I chose the $80,000 threshold because it represents the top 25.6% of all households.

Sources: Harris County Justice Information Management System (JIMS) with 128 days of arrest data between January 1, 2016 and June 30, 2016, Median Household Income by Census Block, additional shape files and census data added for other cities in Harris County.

Questions For the Low Level Marijuana Policy Discussion

  • What are the costs to the government associated with these arrests? Every time someone is arrested, there are full-time employee costs associated with processing the arrest and adjudicating the case. How can we get data to quantify these costs?
  • What are the costs to the citizen associated with these arrests? There are short term costs, like paying for your vehicle to be towed and missing work due to incarceration or adjudication. But there are also long term costs to being “in the system,” even if you’re found not guilty. How do we assign values to these things?
  • This data represents arrests from the Harris County Sheriff’s Office HCSO’s Justice Information Management Report. There are dozens of law enforcement agencies with the power to arrest in Harris County. How can we compile a full dataset to get a region-wide look at the cost of low level marijuana arrests? Who is performing these arrests and how are they trained?

I hope that voters in Harris County have a data-driven debate of low level marijuana policies with our Sheriff and District Attorney candidates in this upcoming election season.

Edit (9/15/16): a previous version of this blog attributed arrests to the Harris County Sheriff’s Office. The report containing this data is called Sheriff’s Department Arrest Data. However, HCSO may not be responsible for all of the arrests.


About the Author

Jeff Reichman

Jeff is passionate about using data to make better decisions and reveal new insights. He founded January Advisors and Sketch City, and serves on the board of the League of Women Voters of the Houston Area. Read his full bio on LinkedIn.