Ottumwa Police are investigating a drive-by shooting from over the weekend.  Around 3:15am Sunday, Police were called about someone being shot at a residence on the 800 block of Ellis Avenue.  Officers found a 17-year-old male who had been shot in the leg.  He was taken to Ottumwa Regional Health Center.  Police say the shooting was part of a disagreement over a drug deal.  About 13 rounds from a 9 millimeter handgun were fired from a vehicle as it drove by the residence.  If you have information on this shooting, call Ottumwa Police at 641-683-0661.