The third victim, a school employee, is in serious condition after the shooting at Starts Right Here, a charter school, Des Moines police spokesman Paul Parizek told reporters.
Police later said the injured victim is 49-year-old Altoona resident William Holmes, the founder and CEO of Starts Right Here. He remained hospitalized in serious condition as of Monday night, according to police.
The shooting, which took place inside the school, was reported just before 1 p.m. About 20 minutes later, three potential suspects were taken into custody at a traffic stop about 2 miles away from the school, according to police, ABC News reported,
The shooting was the result of an "ongoing gang dispute," police said.
Preston Walls, 18, of Des Moines, has been charged with two counts of first-degree murder, attempted murder and criminal gang participation, police said. Two additional people remain in custody as the investigation continues, Parizek said.
The victims have not been identified, but police said they were two young men, 18 and 16 years old, respectively.
A motive is unclear, but Parizek said the shooting was "definitely targeted" and "not random."
The shooting came after a massacre Saturday night in southern California in which 11 people were fatally shot at a dance hall by a 72-year-old Asian immigrant who later killed himself as police closed in.
MNA/PR