MEYERLAND (KTRK) -- A 15-year-old boy was accidentally shot and killed by his step-brother Saturday afternoon in Meyerland.The two step-brothers were inside their parents' home to feed and water the family dog. Neither were living at the home.The 20-year-old step-brother, who is in college, was showing his brother the gun when the accident happened."The 20-year-old wanted to show the 15-year-old an automatic pistol, and while handling the pistol he accidentally discharged it," said HPD Homicide Sgt. Joel Burton.The 15-year-old died, despite his step-brother's attempt to save him with CPR. The victim had been shot in the torso, in what police described as a tragic accidental shooting.Police said the oldest son knew where it was kept.The gun belonged to the father of the oldest son, who serves as captain of Precinct 1 Constable Alan Rosen's staff. Investigators say because no juveniles lived in the home, it is not a case of making a firearm accessible to a child.He was in San Antonio when he received a call about the shooting and is "devastated"."I think that's an understatement," said Rosen. "He is devastated beyond belief. This is a tragic, tragic situation. They were relatives, and even if they weren't, it doesn't get more tragic than this."Members of the constable's staff spent Saturday outside the home, comforting friends and family members.The case will be turned over to the District Attorney's Office for review.The name of the victim is not being released at this time.