PHOENIX -- A former high school teacher convicted of sex with a minor was sentenced Friday to four years in prison plus lifetime probation with sex offender terms.

"Thanks to new legislation supported by our office that toughens the punishment for these offenders, we're now able to get a prison sentence instead of just probation for this defendant," said David Telles, deputy county attorney and prosecutor in the case. "I believe that is a more appropriate and just outcome for these crimes."

Thomas Krepelka, 47, was a teacher at Shadow Mountain High School in north Phoenix when he engaged in sexual relations with a 17-year-old female student, according to the probable cause statement filed by the Phoenix police.

Police said the incident occurred March 9 in the bed of Krepelka's truck while it was parked at Roadrunner Park near 32nd Street and Cactus Road. He was arrested at the school a day later.

On Aug. 5, Krepelka pleaded guilty to two counts of attempted sexual conduct with a minor.