New charge for man accused of stabbing his great-grandparents

Lucian Johnston has been charged with aggravated assault after allegedly stabbing his great grandparents on Dec. 29. (FOX 26 Houston)

The man accused of stabbing his great-grandparents is facing a new charge.

Lucian Adrian Johnston, 20, is already charged with two counts of aggravated assault with a deadly weapon for the December 29 attack.

Johnston is now also charged with possessing a prohibited weapon in a correctional facility after he was allegedly found concealing a small knife into a Harris County Sheriff's Office detention facility.

A judge raised his bond from $80,000 to $240,000.

According to court documents, Johnston is accused of stabbing his 92-year-old great-grandmother and 76-year-old great-grandfather on December 29 as they were riding in a minivan.

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Sheriff Ed Gonzalez called Johnston’s 12-year-old brother a hero for stopping the attack from the back seat and taking the knife away from his older brother.

The man and woman who were stabbed are said to be recovering well.