A former high school teacher here in Laredo has been sentenced to more than four years in prison for possessing child pornography. Federal prosecutors announced the sentence today for 53-year-old Jorge Valadez who taught at United South High School. Once Valadez completes his prison term, he must serve 10 years of supervised release. He will also be required to register as a sex offender. Valadez pleaded guilty November 13 to possessing four videos of child pornography.