A suspect in a North Texas shooting is in custody. Arlington police say Timothy Simpkins turned himself in this afternoon along with his attorney. It's believed he shot at least two people inside Timberview High, west of Dallas, during a fight and a 15-year-old is in critical condition. Two other injuries were reported. All are expected to be okay. It's not known what started today's fight inside a classroom, but police and Mansfield ISD are promising a full investigation.