DETROIT >> A Bakersfield, California man was charged with making online threats to blow up two Indiana high schools and extorting underage girls for sexually explicit photos and video, federal authorities said.

Buster Hernandez, 26, was being held in California today, but was expected to be sent to Indiana to face charges filed Friday of sexual exploitation of a child and threats to use an explosive device.

Hernandez is believed to have used the online moniker “Brian Kil” to contact random individuals — typically minors — through private messages and threatening to send sexually explicit images to their friends and families if they failed to send him more of the images, according to a complaint filed in U.S. District Court in Indianapolis.

“Brian Kil” is believed to have had victims in at least 10 federal districts and has been the subject of an investigation since December 2015.

A Plainfield, Indiana girl was threatened via Facebook in December 2015 after she refused to send sexually explicit photos of herself over the internet. The threats prompted the Dec. 17, 2015, closings of Plainfield and Danville high schools and a shopping center.

A person using the name “Brian Kil” referring to Plainfield wrote to the girl: “I want to leave a trail of death and fire,” the complaint said.

“I will simply WALK RIGHT IN UNDETECTED TOMORROW,” the person continued. “Once in, I will wait a few classes before I start my assault. I’m coming for you. I will slaughter your entire class and save you for last.”

Taunts and threats also were directed toward police. “The police are useless,” the person wrote. “I’ll add a dozen dead police to my tally … tomorrow will be a (expletive) bloodbath at Plainfield High.”

Earlier that week, threatening emails were sent to other school districts across the country. Schools in Los Angeles were closed for a day.

Tim Horty, a spokesman for the U.S. Attorney’s office in Indianapolis told The Associated Press in an email today that he didn’t know if Hernandez was a suspect in those cases.

Josh Minkler, U.S. Attorney in Indianapolis, told reporters today that the person known as Brian Kil — in his own words — “wanted to be the worst cyber terrorist that ever lived.”

“The evidence shows he was well on his way to achieving that goal,” Minkler said.

The complaint against Hernandez also says an underage Michigan girl was threatened if she didn’t send sexually explicit images and videos. She no longer is a minor.

A second Indiana girl was asked to attend a Jan. 19, 2016, community forum at Plainfield High School and relay what was discussed back to him.

The affidavit also says the person going by the name “Brian Kil” attempted to cover his cyber tracks by using computer software designed to make communications over the internet anonymous.

On Feb. 4, 2016, “Brian Kil” posted “it would take a miracle to catch me” to Facebook accounts.

But authorities, in June, tracked the communications to a computer at the Bakersfield home of Hernandez’ girlfriend.

Computer equipment and removable data storage devices, such as thumb drives, were seized from the home, Minkler said.

Hernandez shares the home with his girlfriend Kimberly Francis and her grandmother, Audrey Francis.

“My God! I’m so disappointed,” Francis told The Associated Press today in a telephone interview. “He’s taken care of me and I’m 87 years old. When I took my fall — about a year ago — he took care of me.”

Audrey Francis said her granddaughter is “in tears,” adding “I don’t believe it happened and she can’t believe it happened.”