HILLSBOROUGH, Co., Fla — Douglas Earl Kersey is accused of using the YouVersion Bible App to secretly reach out to underage girls at a Hillsborough County church youth group.

According to a warrant, Kersey was eventually charged thanks to an observant congregation member who noticed the odd online behavior and notified the Florida Department of Law Enforcement.

“She's a hero to me, she's a real hero,” said Reverend Russell Meyer. He’s part of the Lutheran Parish of Tampa and heads two churches. To his knowledge, his churches are not involved in this case.

Court documents show FDLE received the tip in late September. The churchgoer told the agency Kersey was using the Bible App so he can “befriend young teenage girls in their church and communicate with them online.” The Bible App touts itself as being on over 350 million devices worldwide.

“Unfortunately it's not surprising,” said Rev. Meyer. “There's a world of nasty people who want young children and open platforms give them an open door to them.”

The churchgoer told the investigator she became suspicious of Kersey’s activity and searched his name online after he friend requested several teenage girls in their youth group.

“It was unheard of for me and I've been with the sheriff's office 21 years and been an investigator, school resource deputy,” said Detective Theresa Grooms, who worked the case for HCSO. “I did not even know that they could friend request and converse on that app.”

The tipster learned Kersey was a registered sex offender after looking up his name. She told investigators Kersey’s list of friends consisted mostly of young females. The girls in her church group who accepted his friend request are all minors and “that was concerning to her.”

“It was very concerning,” said Grooms, “You have young ladies that are meeting in a youth group to study the Bible, study the church activities and you have a registered sex offender who has projected himself into that group.”

The FDLE researched Kersey and realized he failed to do one of the 22 legal rules and regulations sex offenders sign and acknowledge they will adhere to. According to the court documents, Kersey did not disclose to HCSO any email addresses, websites, and profiles to social media accounts he was using, including the Bible App. Failure to report the information is a third degree felony.

“So simply to say ‘well it's a Bible program, nothing could go wrong' misunderstands who is allowed to use them,” said Reverend Meyer of the app.

Kersey has a criminal history of unlawfully communicating with minors. In 2013, he spent nearly three years in prison for transmission of material harmful to minors and unlawful use of a two-way communication device.

Kersey admitted to HCSO and FDLE investigators he did not tell them about a gmail account he was using. He also admitted to actively using the Bible App. Investigators found the app open on his phone after he agreed to a search.

“I’m really happy to actually hear about the intervention that happened because too often we hear about something terrible that happened to a child too late,” said Rev. Meyer.

Grooms has one piece of advice for parents.

“Be aware. Check their social media, check their phones, check their email addresses, check their friends. Then you have to double and quadruple check.”

The Hillsborough County Sheriff’s Office will not name the church involved because of its interpretation of Marsy’s Law. The agency is looking into whether there are any other apps Kersey may have used to illegal communicate with minors.