KING OF PRUSSIA, PA — A California man posed as a fitness guru on social media to sexually abuse underage girls from Montgomery County and around the country, federal authorities said. Officials believe there are even more victims from the local area, and are asking them to come forth as they build their case.

John Douglas Burch, 54, of Santa Monica, victimized young girls for more than 10 years, from 2014 through early 2024, the FBI said.

Burch used Instagram and other social media platforms to create an identity for himself as a fitness professional, pressuring young female clients to partake in what he called a “sex slave training program,” the FBI said.

Find out what's happening in Norristownwith free, real-time updates from Patch.

The “training” involved having the children watch violent pornography, create porn of themselves and send it to him, create online dating profiles that ultimately became advertisements for prostitution, and more, according to the U.S. Attorney’s Office.

Burch also provided step by step instructions on what specific sexual acts the girls had to perform and record with photos and videos, police said.

Find out what's happening in Norristownwith free, real-time updates from Patch.

It’s unclear exactly how many of these victims Burch met in person and raped himself, although meetings occurred in both King of Prussia and West Conshohocken, as well as in North Carolina and California, according to authorities.

“The FBI believes that once the victim was ‘trained’ to Burch’s liking, he would meet the victim in person and force her to partake in illegal and non-consensual sexual acts,” the agency shared.

In addition to Instagram, Burch used Kik, Omegle, Snapchat, Telegram, Facebook, Twitter, Reddit, Discord, Seeking Arrangements, and Fetlife. His usernames included Burch, Mstr_trainer, Just9x6.5a, Notyourfitguru, TheBurch9567, NOTYOURFITGURU, food_is_not_enemy, notyourfitguru2, not_your_fit_guru_original, and backup_notyourfitguru.

If you had any contact with these usernames, or know someone who did, contact the FBI at or fill out this online form.

Get more local news delivered straight to your inbox. Sign up for free Patch newsletters and alerts.

Click Here: Gold Coast Suns Guernsey