A man who gave his son the gun he used to kill two students and two teachers at Apalachee High School in Georgia was sentenced Thursday to 15 years in prison. Colt Gray had pleaded guilty to murder and other charges. A jury in March found Colin Gray guilty of second-degree murder in the deaths of two 14-year-old students, Mason Schermerhorn and Christian Angulo. Prosecutors said Colin Gray missed red flagsProsecutors say Colin Gray gave his son the rifle as a Christmas gift along with ammunition, a gun sight and other shooting accessories. Like Colin Gray, they were unaware of their son’s plans but had gifted him a gun before the shooting.