Purdue faculty develop algorithm tool to help authorities identify online sex offenders
WEST LAFAYETTE, Ind. – Faculty at Purdue Polytechnic Institute have developed an algorithm tool designed to help authorities filter out and focus on sex offenders most likely to set up face-to-face meetings with child victims.
Using algorithms, the Chat Analysis Triage Tool (CATT) allows officers to examine the word usage and conversation patterns of suspects. Kathryn Seigfried-Spellar, the principal investigator on the project, said developers used data provided by law enforcement around the country.
“We went through and tried to identify language-based differences and factors like self-disclosure,” she said.
Self-disclosure is a tactic in which the suspect tries to develop trust by sharing a personal story, which is usually negative, such as parental abuse.
“If we can identify language differences, then the tool can identify these differences in the chats in order to give a risk assessment and a probability that this person is going to attempt face-to-face contact with the victim,” Seigfried-Spellar said. “That way, officers can begin to prioritize which cases they want to put resources toward to investigate more quickly.”
Other standout characteristics of sexual predators grooming victims for a face-to-face meeting is that the chats will often go on for weeks or even months until a meeting is achieved. Those involved in sexual fantasy chatting move on from one youth to another quickly.
Seigfried-Spellar said research discovered tactics like self-disclosure is used early in a predator’s talks with a potential victim.
“Meaning that we could potentially stop a sex offense from occurring because if law enforcement is notified of a suspicious chat quickly enough, CATT can analyze and offer the probability of a face-to-face,” she said. “We could potentially prevent a child from being sexually assaulted.”
CATT algorithms examine only the conversation factors and do not take the sex of either suspect or victim into consideration, at this time.
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.