An algorithm tool developed by Purdue Polytechnic Institute faculty will help law enforcement filter out and focus on predators most likely to set up face-to-face meetings with under age victims.
The Chat Analysis Triage Tool (CATT) was presented last week by principal investigator Kathryn Seigfried-Spellar, assistant professor of computer and information technology, at the International Association of Law Enforcement Intelligence Analysts Conference in Anaheim, California.
CATT allows the officers to work through the volume of solicitations and use algorithms to examine the word usage and conversation patterns by a suspect. Seigfried-Spellar said data was taken from online conversations provided voluntarily by law enforcement around the country.
The project started as a result of a partnership with Ventura County Sheriff’s Department in California.
Seigfried-Spellar said the research discovered tactics like self-disclosure is used early in a predator’s talks with a potential victim.
Seigfried-Spellar worked in developing CATT with two co-principal investigators, associate professor Julia Taylor Rayz, who specializes in machine learning and natural language processing, and computer and information technology department head Marcus Rogers, who has an extensive background in digital forensics tool development.
CATT algorithms examine only the conversation factors and do not take the gender of either suspect or victim into consideration, at this time.
The project began with initial research done by Seigfried-Spellar and former Purdue professor Ming Ming Chiu. The exploratory study examined more than 4,300 messages in 107 online chat sessions involving arrested sex offenders, identifying different trends in word usage and self-disclosure by fantasy and contact sex offenders using statistical discourse analysis.
The trends determined through this research formed the basis for CATT. The research, “Detecting Contact vs. Fantasy Online Sexual Offenders in Chats with Minors: Statistical Discourse Analysis of Self-Disclosure and Emotion Words,” has been accepted and will be published in the journal “Child Abuse and Neglect.”
Initial plans are to turn the tool over to several law enforcement departments for a test run. Seigfried-Spellar said CATT could be handling data from active cases as early as the end of the year.