15-year old Texas girl critically injured by 10-year old brother, who then fatally shot himself

10-year old Coby Tucker was at home with his mother an sister in Bedias, Texas, just west of Huntsville, when he accessed a loaded, unsecured handgun.  He then went into the room of his 15-year old sister, Ashley Tucker, and fired at her multiple times.  He then turned the gun on himself and committed suicide.

Ashley is in the hospital in good condition.

From an article and news video:

Investigators have not said how Coby got the gun, but they did say that the family has a gun safe in the home. The motive for the shooting is under investigation. 

Deputies said the children's mother was at home at the time of the shooting but was apparently unaware that her son had a gun. 

"Once she heard the shots, she responded and called 911," Detective Greg Williams said. 

The children's father was at work at the time of the incident, investigators said. 

Officials have not said if the parents will face any charges.

From another article:

After investigating the crime scene, deputies said they believe that Coby Tucker got access to the handgun from a locked safe in the home. No charges have been filed in the shooting. 

“There is no reason for us to believe that this was a case of negligence by the parents,” Walker County Sheriff Clint McRae said. “The firearm was in a secure safe, but the boy was somehow able to gain access. This is a terrible tragedy that happened and our thoughts are with the family.”

Every gun in the hands of a child must first pass through the hands of an adult.