A US teenager who shot dead four people at a high school with a gun his father gave him as a Christmas present was sentenced to life in prison on Tuesday.Colt Gray, 16, pleaded guilty to carrying out the September 2024 attack at Apalachee High School in the town of Winder, Georgia.Gray was 14 years old when he shot dead two 14-year-old pupils and two teachers, while also wounding nine other people. He was charged as an adult.Superior Court Judge Nicholas Primm sentenced Gray to life in prison...