***UPDATE THURSDAY 12:40 P.M.***17-year-old Marquez F. Marshall remains in the Boone County Jail as of Thursday afternoon on a $9,000 bond. He is charged with second degree robbery and second degree assault.Boone County Assistant Prosecutor Andi Hayes has requested a bond of $100,000. She is also seeking to ban Marshall from all Columbia Public Schools property and Douglass Park. She also wants the judge to order Marshall to stay away from the victim.Jefferson Junior High School is increasing security after the incident on Wednesday.”Safety is always our number one concern, make sure they feel safe on campus,” said Columbia Public Schools spokesperson Michelle Baumstark.The school has added private security and police patrols while working on and updating their security protocol.***UPDATE 8 P.M.***Police say 17-year-old Marquez F. Marshall turned himself into authorities in reference to the attempted robbery at Jefferson Junior High School in Columbia.Marshall was arrested on charges of second degree robbery and third degree assault.***ORIGINAL STORY***Columbia police are investigating an attempted robbery near Jefferson Junior High School Wednesday afternoon.Around 3:30 p.m., a female teacher was walking to her vehicle when a man approached her and asked for her keys. When the woman refused to hand over her keys, the suspect punched the woman in the face and then fled the scene.Jefferson Junior High School was briefly placed on a lockdown. Parents of students at the school say they are receiving recorded phone calls from the principal stating the school will be increasing patrols and changing security procedures.No arrests have been made and the only suspect description police have is a black male, 6 feet tall with short black hair and wearing a grey shirt.The woman was taken to a local hospital for her injuries.