SDSU Research Team Identifies Victims of Sex Trafficking


Identifying key words in online advertising may help law enforcement track and arrest perpetrators

According to law enforcement officials, California has become a major hub for human sex trafficking. With this in mind, researchers at San Diego State University (SDSU) found that traffickers are increasing using Internet advertising, disposable phones and mobile devices to ply their illegal wares. They also found a tool – knowledge management (KM) – that can potentially be used to detect and shutdown traffickers and rescue victims.

The research was conducted by SDSU graduate student, Marisa Hultgren, and her thesis supervisor, Dr. Murray Jennex, SDSU professor of management information systems. They reported finding that expanding technology has allowed pimps to advertise trafficking victims more quickly and easily than ever before all while moving from city to city in order to stay ahead of law enforcement. 

They also noted that traffickers who use online advertising – specifically on sites such as Craig’s List and Backpage.com – frequently use specific wording in the ads that indicate that the victim may be a minor (“fresh”, “barely legal” “new in town”), may be open to unconventional sex acts (“open minded”) or may be closely watched in order to restrict the victim’s movements (“incalls only”).

The researchers then used knowledge management to analyze the ads to find similarities. Jennex, defined knowledge management as “the practice of selectively applying knowledge from previous experiences of decision-making to current and future decision making activities with the express purpose of improving an organization’s effectiveness.”

They gathered data from highly referenced articles and academic works to establish a baseline from which they could review and reference. Next they pulled 4836 ads that had one or more indicators of trafficking from the “Female Escort” section of Backpage.com that ran from February 11, 2015 – February 16, 2014 from 15 different California cities and eventually compiled into a Microsoft Excel file using verbiage from those ads into the following categories:
1. Location of ad posting
2. Advertised age
3. Text included in the ad
4. Phone number
5. Title of ad
6. URL
7. Date/time

Hultgren and Jennex then further extracted data from the ads to determine signs that they may have been placed by sex traffickers by matching the frequency of similarities to the other ads or to their list of keywords and phrases:
1. Duplicate ads/phone numbers (54%)
2. Reference of ethnicity/national origin (28.2%)
3. Unconventional sex advertised (13.4%)
4. Disguised phone number (12.5%)
5. Out-of-state area code (12.1%)
6. Restricted movement (11.8%)
7. Transient language (9.0%)
8. Indications of working in a group (8.8%)
9. Under 18 keyword indicators (5.2%)

NOTE: A disguised phone number may consist of putting random characters between the numbers, writing out the numbers, or using letters instead of numbers (like “o” for “0”, etc.).

Upon further investigation, the researchers found that many of the individual ads contained multiple keywords and phrases, especially when describing potential minors and that a few identical phone numbers were placed in a disproportionation number of ads.

In conclusion, Hultgren and Jennex noted that as a central hub for sex trafficking, California should lead the charge in developing innovative methods to combat this crime. “The state must continuously work to improve counter trafficking measures,” he said. “Using a KM approach coupled with successful cases in rescuing trafficking victims and periodically searching/updating keywords will keep the data bases for the system accurate. This is not the only tool needed to combat sex trafficking, but it could keep potential victims from falling through the cracks.”