COLUMBIA, Mo. -

A Columbia teenager has been sentenced to prison for assaulting and attempting to rob a Jefferson Junior High School teacher.

Marquez F. Marshall will spend nine years behind bars after the court found him guilty of second-degree attempted robbery and second-degree burglary.

On November 7, 2012, a female teacher was approached by Marshall in the school's parking lot and he asked for her keys. When she refused, he punched the woman in the face then fled the scene.

Because of the assault, Jefferson Junior High School was briefly placed on a lockdown.

Marshall later turned himself into police.

On Monday, the judge sentenced him to four years in prison for the attempted robbery charge and five years for the assault charge.