A federal judge has sentenced a former substitute teacher in Carver County to 40 years in prison for creating online personas of girls to trick dozens of boys and adults into sending him nude pictures and videos, then threatening to share the images widely if they didn't send more.

Mitchell James Ottinger, 25, was sentenced Friday in U.S. District Court in St. Paul for using variations of screen names "Rachel Meyer" and "Taylor Malek" to contact potential victims on social media apps such as Snapchat since 2013 as part of his "sextortion" scheme. Some of them he knew from the Eastern Carver County School District where he worked, according to the U.S. Attorney's Office.

Judge Wilhelmina Wright's sentence was 20 months longer than what prosecutors sought. The defense argued for a 15-year prison term.

Ottinger, of Carver, pleaded guilty in October to two counts of production and attempted production of child pornography and one count of interstate communication with intent to extort. His sentence includes 25 years of supervision after he leaves prison.

"Today's crippling sentence reflects the heinous nature of the defendant's crimes, as he used his position of trust and authority to find his victims, and traumatize them," FBI special agent in charge Michael Paul said in a statement following Ottinger's sentence.

Defense attorney Kurt Glaser declined to comment Tuesday about his client's sentence.

Sextortion cases are difficult to track, according to authorities, in part because they are underreported. The FBI issued a public service announcement last summer saying it received more than 16,000 sextortion complaints in 2021.

"Sextortion is a crime that can victimize any child," Paul added, "and the FBI will continue to work with our partners and in our communities to make sure our children know that help is available and that we will spare no effort in hunting down their predators."

Ottinger sent explicit videos of the girls he purported to be, encouraging the victims to create and send back sexually graphic videos of themselves. He then threatened to send those images to the victims' family and friends if they didn't continue to send more.

In one case, a 15-year-old victim blocked Ottinger on social media, and Ottinger texted him a nude photo of the boy exposed in front of a mirror. "Unblock me and be a good boy or I'll show my friends … U can't just ghost me," Ottinger wrote, according to charging documents.

In a court filing ahead of sentencing, prosecutors alleged that Ottinger exploited at least 42 people, most of them children.

"Ottinger targeted these young boys and others not only to satisfy his appetite for images of the sexual abuse of children, but for the thrill of humiliating his victims," the prosecution's pre-sentence filing read. "He threatened to disseminate sexually explicit images produced at his behest, and actually did so, including to the victims' friends and family members. ... For Ottinger, cruelty was not just a side effect: it was the point."