(CNN) -- Investigators believe an 8-year-old boy intentionally shot and killed his 90-year-old grandmother on Thursday evening after playing a violent video game.

The woman, Marie Smothers, was pronounced dead at the scene with a gunshot wound to the head in a mobile home park in Slaughter, Louisiana, the East Feliciana Parish Sheriff's Office said in a statement. Slaughter is about 20 miles north of Baton Rouge.

The boy initially told investigators he accidentally shot his grandmother while playing with a gun, but after further investigation officials determined it was a homicide.

The boy won't face charges. Under Louisiana law, a child under 10 is exempt from criminal responsibility.

Before the incident Smothers had been watching TV in the living room while the boy played a video game in which players shoot people.

"Although a motive for the shooting is unknown at this time investigators have learned that the juvenile suspect was playing a video game on the Play Station III "Grand Theft Auto IV", a realistic game that has been associated with encouraging violence and awards points to players for killing people, just minutes before the homicide occurred," a release from the sheriff's office stated.

There has long been debate about whether virtual violence in video games leads to actual violence.

Colorado Gov.

"There might well be some direct connection between people who have some mental instability and when they go over the edge - they transport themselves, they become part of one of those video games," Hickenlooper said on CNN's "State of the Union." "Perhaps that's why all these assault weapons are used."

Smothers was the boy's caregiver, and the pair shared a bedroom, CNN affiliate WAFB reported.

"We have a child who does not know the impact of the consequences of the act he committed," Sclynski Legier, a lawyer, told WAFB. "He truly doesn't understand that."

He is now with his parents.