12-year-old boy fends off older brother, 20, saving his great-grandparents in stabbing attack

Police say a 12-year-old Texas boy saved the lives of his great-grandparents this week, when he fought off his 20-year-old brother who began stabbing the elderly victims in a fit of rage.

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Lucian Johnston, 20, was arrested Monday, accused of using a pocket knife to stab his great-grandparents — ages 92 and 76 — in the head and neck. The alleged attack occurred Sunday night while the elderly victims were in a vehicle with Johnston, and dropping him off at a friend's house.

According to the Harris County Sheriff's Office, Johnston's 12-year-old half brother, who was also in back seat of the vehicle with Johnston, was able to wrestle the knife away from the suspect and throw the weapon out the car window.

Both victims were treated for their wounds and are expected to recover, according to Harris County Sheriff Ed Gonzalez, who said the 12-year-old is a "hero" who "truly prevented a double murder." The 12-year-old was not injured in the attack.

In a news conference Monday, Harris County Sheriff's Sgt. John Klafka said Johnston was "set off" after his great-grandmother informed him that he could not return to live in their home until he had been evaluated by a doctor due to his "behavioral issues," ABC News reported.

After the attack, Johnston fled the vehicle. Law enforcement was able to apprehend him the next day, and he is currently in jail on two counts of assault with a deadly weapon.