College student uses SnapChat filter to launch sting that nabs cop

SOUTH BAY, CA (NBC) - A college student in California used a SnapChat filter to take down a cop who was allegedly looking to hook up on Tinder.

Ethan is a 20-year-old student in the South Bay area.

He told police he had a female friend who had been molested as a child and went online to create an undercover profile to identify possible pedophiles.

The student, who did not give his last name because he fears retaliation used the SnapChat gender switch filter to take a picture of himself and hen posed as a woman named "Esther" on tinder.

According to Ethan, a man reached out to him asking, “Are you down to have some fun tonight?"

Ethan then texted the man on a different app, saying that he was 16-years-old.

Ethan said it didn't appear to matter to the suspect because they began exchanging explicit messages for more than 12 hours.

Ethan took several screen-shots of their conversation and sent them to "Crime Stoppers."

He was arrested last week on suspicion of discussing sexual activity with a minor on social media.