Updated

A 10-year-old suspected of fatally shooting his father a month ago after watching his parents endure a bitter divorce has been charged with murder.

The boy was charged last week in the Aug. 27 death of Dr. Rick Lohstroh (search), lawyer David Matthews said.

The 41-year-old physician was shot outside the Katy home of his ex-wife, Deborah Geisler, after he arrived to pick up his two sons for a weekend visit following a divorce that included unproven allegations of sexual abuse of the 10-year-old by the father.

Investigators say the boy, who was taking the anti-depressant Prozac (search) at the time of the slaying, took a pistol from the home, climbed into the back seat of his father's sport utility vehicle and shot Lohstroh in the back.

If allegations against the 10-year-old are found to be true in juvenile court, he could be held as a youth until age 18 and then could be imprisoned for an additional 40 years, a lawyer for the boy has said.

The boy remained Thursday in the Harris County Juvenile Detention Center (search). His brother is with their grandparents, who were granted custody of both boys.

A hearing is scheduled for Oct. 5, said Matthews, who represents the grandparents in a lawsuit against Prozac's manufacturer.

Matthews told the Houston Chronicle for Thursday's editions he could not discuss anything further about the boy or the charges against him.

On Sept. 15, Juvenile Court Judge Kent Ellis imposed a gag order prohibiting the boy's relatives and lawyers in the case from providing information to reporters. The order came at the request of attorney Brian Fischer, who was appointed to represent the child's interests during the criminal proceedings.