Indianapolis police say a 15-year-old boy has been arrested in the fatal shooting of two teenage siblings, the AP reports. The Indianapolis Metropolitan Police Department says the juvenile was arrested Monday afternoon; sources tell Fox 59 the teen's mother negotiated his surrender. He is suspected in the killings of 16-year-old Nicholas Nelson and his 15-year-old sister, Ashlynn Nelson, in an Indianapolis apartment on Friday. Marion County prosecutors will review the case and make a charging decision. Under Indiana law, a judge must decide whether defendants under the age of 16 accused of murder are tried in adult or juvenile court. Police officers who attended the scene of the shooting said a male fled when they arrived. WXIN-TV reports that a vigil was held Sunday for the siblings, who were Lawrence North High School students. (More Indianapolis stories.)