The app asks travelers to snap photos of any hotel rooms they stay in. Police are also asked to feed the database with photos from escort advertisements depicting minors in hotel rooms. Algorithms then analyze the two sets of photos to try and find a match.

App initiator Molly Hackett says the technology could potentially speed up detectives’ response to a location of a pimp or victim.
The FBI’s St. Louis division says it is excited about the new technology. St. Louis has been identified by the FBI as being among the top 20 metropolitan areas in the U.S. with a high level of sex trafficking.
"In this case, individual citizens who want to help stop sex trafficking but didn’t know how, now have a tangible way to contribute," said William Woods, the special agent in charge of the FBI’s St. Louis Division.

The Congregation of the Sisters of St. Joseph, a social justice group, is hopeful of the app’s potential and has donated a $100,000 matching grant toward development.
Conference planners Hackett, Jane Quinn, Kimberly Ritter teamed with Washington University computer programming researcher Abby Stylianou, to create the app.
Hackett, Quinn and Ritter founded a resource center on sex trafficking, and in 2014 they started crowdsourcing travelers for cellphone photos of hotel rooms for a website they wanted to develop for law enforcement.
"There aren’t many opportunities for anybody on any given day to make a difference in sex trafficking, but with this app, you really can," Hackett said.
Stylianou said test trials show that about 85 percent of the time, the algorithm is able to deliver a hotel match in the first 20 photos its returns from the search.

The app’s creators said more than 1.5 million photos have been uploaded to the database from more than 145,000 hotels, but Stylianou said significantly more is needed.
She said most of the photos have been scraped by a Washington University computer lab from internet travel sites.
"Those are not necessarily the rooms where the victims are being trafficked," she said. "The reality is we believe we can do even better by getting pictures from the app that more accurately represent the hotels. So getting these pictures from travelers is hugely important."

San Francisco Chronicle © June 2016