By Lauren Rearick

A 20-year-old California college student used an augmented-reality photo effect on Snapchat that adjusts its users's photos to adhere to more traditionally feminine codes — and in doing so, he took down a predatory police officer attempting to engage in sexual activity with someone he knew to be underage.

The San Jose Police Department confirmed that Ethan, a college student from the San Francisco Bay area who only wanted to be identified by his first name, decided to use the filter to pose as a female user on Tinder, NBC Bay Area reported. Ethan, who assumed the identity of Esther, told NBC Bay Area that after a friend had shared their account of childhood sexual misconduct, he decided to pose as female on the dating app in an effort to catch local pedophiles.

Ethan had listed his age as 19 years old on Tinder, which requires that users are 18 or older; he then filtered the augmented photo to make Esther look younger, the San Jose Police Department said in a statement. A man, who police would later identity as 40-year-old Robert Davies, a police officer from the San Mateo Police Department, initially contacted “Esther” on Tinder, asking, “Are you down to have some fun tonight?”

The conversation, which started on May 11, 2019, was moved by both parties to Kik, where Ethan told Davies that “Esther” was 16 years old. Davies later asked for the conversation to be moved to Snapchat, where Ethan repeated that Esther was only 16. Ethan told NBC Bay Area that the conversation lasted for 12 hours, and conversations “got more explicit.” According to the investigation, the 40-year-old officer denied being bothered by Esther’s reported age.

Ethan later alerted authorities to the conversation, and San Jose Police began an investigation on May 13, 2019. Police arrested Davies on June 6, 2019, and he was booked in the Santa Clara County Jail on one charge of contacting a minor to commit a felony; his bail was set at $50,000.

San Mateo Police Department confirmed it placed Davies on paid leave when the investigation started. San Mateo Police Chief Susan Manheimer said in a Facebook statement that the officer’s conduct is not “a reflection of all that we stand for as a Department, and is an affront to the tenets of our department and our profession as a whole.”

Ethan told NBC Bay Area that he never intended to discover a cop through his unofficial investigation, rather he “was just looking to get someone.”

Although Ethan was able to assist police through his use of Snapchat, Kelvin Coleman, Executive Director at the National Cyber Security Alliance, does not recommend for others to pursue similar action. “We have very dedicated law enforcement officials who do that for a living,” he said. “This situation turned out really well, but the outcome could have been different in other circumstances. If you’re not trained in this, and if you’re not doing it in the right way, you could end up in a very bad situation.”

Internet-based sexual misconduct is an ongoing issue in the U.S. The Department of Justice reported that 1 in 7 adolescent Internet users experience “unwanted Internet solicitation” and in 76 percent of those cases, the encounter started in an internet chat room. However, apps including Kik and Snapchat have also become popular places for online predators.

Adam Scott Wandt, assistant professor of public policy at John Jay College of Criminal Justice, told WBUR that Snapchat’s rising popularity among predators is due in part to how Snapchat operates. Users can set a timeframe for their photos to disappear, and this makes it difficult for authorities to discover potential predatory behavior. “If law enforcement doesn't know that this is going on and they don't get to Snapchat on time with their legal process to request or to preserve the evidence, they lose it forever,” Wandt explained.

In order to protect yourself from unwanted followers or conversation, Coleman suggested always assessing your online privacy settings, especially the options located within individual apps.“Make sure you’re sharing information with who you really intended to be sharing with,” Coleman said. “Think before posting about yourself and others, because once it’s out there, it’s hard to take back.”

Snapchat does have a number of safety measures in place, including an in-app reporting function and a requirement that users be at least 13 years old in order to use the app. Kik had also told the New York Times that it was working with law enforcement to prevent child exploitation.

MTV News has reached out to Snapchat and Tinder for comment.