A former Bemidji assistant school principal pleaded guilty Thursday to two felony counts of producing and distributing child pornography and the coercion and enticement of a minor, Acting United States Attorney Gregory G. Brooker announced.

While Brandon Mark Bjerknes, 35, was assistant principal of Bemidji Middle School, he posed as a 13- to 15-year-old named "Brett Larson" on Facebook and on Snapchat to contact middle school and high school girls and boys, according to the guilty plea. Bjerknes reportedly engaged in sexually explicit conversations and directed minors to send him sexually explicit photographs.

Bjerknes began work with the Bemidji Area Schools in 2006 and served as assistant principal of Bemidji Middle School until April. He was charged and arrested on May 30.

"Brandon Bjerknes repeatedly victimized vulnerable young girls and boys, many of whom he personally knew because of his former role as Assistant Principal of Bemidji Middle School," said the prosecutor, Assistant U.S. Attorney Angela Munoz-Kaphing, in a statement. "Due to a vigilant parent who initially reported disturbing social media messages, and the dedicated efforts of the Beltrami County Sheriff's Office and the Minnesota Bureau of Criminal Apprehension, Bjerknes' predatory actions were stopped."

Authorities said Bjerknes used the alias social media accounts to contact more than 50 minor victims, including students at Bemidji Middle School.

Karen Zamora • 612-673-4647

Twitter: @KarenAnelZamora