12-year-old stops back-seat knife attack of great-grandparents near Katy, sheriff says

The Mason Lakes subdivision is seen on Google Maps. The Mason Lakes subdivision is seen on Google Maps. Photo: Google Maps Photo: Google Maps Image 1 of / 3 Caption Close 12-year-old stops back-seat knife attack of great-grandparents near Katy, sheriff says 1 / 3 Back to Gallery

A 12-year-old managed to wrestle a knife away from his 20-year-old half-brother as the elder stabbed his great grandparents from the back seat of a moving car, Harris County Sheriff Ed Gonzalez said.

The boy was in the back seat of his great-grandparents’ car along with with Lucian Adrian Johnston when Johnston and the elderly couple began to argue, according to the Harris County Sheriff’s Office. The four were driving in a neighborhood near Clay Road and the Grand Parkway sometime Sunday night when the argument started, authorities said.

At some point during the argument, Johnston pulled a pocket knife and began stabbing his 92-year-old great grandmother and 76-year-old great grandfather in the head and neck, police said. The quick-thinking 12-year-old lunged at Johnston and wrestled the knife away before grabbing and tossing it out the window of the moving car.

“He truly prevented a double-murder,” Gonzalez tweeted.

They eventually stopped in the 4200 block of Mount Vinson Way where Johnston got out of the car and fled on foot, authorities said. The two great grandparents were treated at a nearby hospital for non-life-threatening wounds, according to HCSO.

Deputies scouring the Mason Lakes subdivision for Johnston arrested him Monday morning on two counts of aggravated assault with a deadly weapon.

Gonzalez praised the young boy and acknowledged that the incident is a lot to handle, especially for someone his age.

“I’ve talked lately about my worry for the trauma impacting so many in our modern era,” Gonzalez said. “Surely, this entire family, including the 12 (-year-old), has new trauma to process.”

Jay R. Jordan covers breaking news in the Houston area. Read him on our breaking news site, Chron.com, and our subscriber site, HoustonChronicle.com | Follow him on Twitter at @JayRJordan | Email him at jay.jordan@chron.com