A man who gave his son the gun he used to kill two students and two teachers at Apalachee High School in Georgia has been sentenced to 15 years in prison. Colt Gray (Jason Getz/Atlanta Journal-Constitution via AP) (Jason Getz/Jason Getz/Pool Atlanta Journal-)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. Georgia law defines second-degree murder as causing the death of a child by committing the crime of cruelty to children. The assault rifle used in the Apalachee High School shooting (Jason Getz/Atlanta Journal-Constitution via AP) (Jason Getz/Jason Getz/Atlanta Journal-Const)Colin Gray was also convicted of multiple counts of reckless conduct and cruelty to children. Prosecutors said Colin Gray gave his son the rifle as a Christmas gift along with ammunition, a gun sight and other shooting accessories.