UPDATE: Former Tennessee teacher Tad Cummins was sentenced to 20 years in federal prison in the 2017 kidnapping of a 15-year-old girl student.

Cummins, 52, pleaded guilty in April 2018 to federal crimes of crossing state lines to have sex with a minor and obstruction of justice.

Prosecutors said in a criminal complaint after his 2017 arrest that Cummins took his victim across state lines in order to engage in "criminal sexual activity."

NBC News does not name victims of sexual abuse.

Cummins faced a mandatory minimum sentence of 10 years in prison for crossing state lines for sex with a minor and up to 20 years for obstruction of justice, the Associated Press reported.

The former teacher in Columbia, Tennessee, was arrested in Northern California in April 2017, more than a month after he and his 15-year-old victim disappeared, sparking a nationwide search.

Authorities found Cummins and his victim after a tip came in saying the pair might being living "in a cabin in a remote area" of Cecilville, California.

Cummins had been suspended from his teaching job at Culleoka Unit School on Feb. 6, 2017, after another student saw him kissing his victim, according to a criminal complaint.

On the morning of March 13, 2017, Cummins left a note for his wife claiming he was leaving to "think" and asked her not to call the police. His victim was reported missing by her father later that evening.

Cummins was fired the day after an Amber Alert was issued by the Tennessee Bureau of Investigation. His teaching license was later revoked by the Tennessee Board of Education.

PREVIOUS STORY: NASHVILLE, Tenn. — A teacher who entered a guilty plea on two counts involving the cross-country trip he took with a 15-year-old Tennessee high school student could face a sentence of 30 years in prison under recommendations by the prosecution.

Tad Cummins faces a mandatory minimum sentence of 10 years in prison on two charges, transporting a minor for sex and destroying evidence, and destroying both their cell phones.

Cummins admitted he took the student on a cross-country trip that began March 13, 2017. Along the way, they stole license plates in Alabama, Mississippi, Louisiana, Utah, Nevada, and Oklahoma to avoid being caught. The two bought a kayak in an attempt to paddle from California to Mexico but the water was too rough.

Investigators found Cummins and the girl in California five weeks after they disappeared living in a cabin on a commune. Cummins admitted to having sex with the teen several times.

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