PORTLAND, Ore. (AP) – A federal judge has sentenced a 50-year-old Tigard man to 15 years in prison followed by a lifetime of supervised release for contacting, grooming and sexually exploiting girls via social media.

The Oregonian/OregonLive reports David Otto was sentenced Wednesday.

An investigation began after the mother of one of Otto’s victims reported to Sonora Police Department in California in November 2016 that her 15-year-old daughter had been having inappropriate communications with an unknown man on Instagram.

Prosecutors say she had engaged in sexual conversations with Otto and, when prompted, sent him nude photos of herself.

Investigators linked the Instagram account to Otto using the IP address.

The FBI took over the case after discovering Otto had engaged in similar online conversations with six other teenage girls who lived around the country.

Otto pleaded guilty in February 2018 to one count of producing child pornography.

Information from: The Oregonian/OregonLive, http://www.oregonlive.com

More about: