Earlier in the day, an assistant district attorney was shot dead near the North Texas county courthouse.
On December 14, 2012, twenty children and six adult victims were fatally shot by a gunman -- who later killed himself -- at the Sandy Hook Elementary School in the town of Newtown in the US state of Connecticut. Earlier in the day, the assailant killed his mother in another location.
There have been reports that the twenty-year-old killer, Adam Lanza, suffered from a personality disorder, was on the antidepressant Prozac, and was fond of first-person shooter games.
Every year, more than 30,000 people are shot and killed in the US.
The US averages 87 gun deaths each day as a function of gun violence, with an average of 183 injured, according to the University of Chicago Crime Lab and the Centers for Disease Control.
The year 2012 was a record setting year for gun sales in the US.
About 4.5 million firearms are sold annually in the United States at a cost of 2 to 3 billion dollars.
At least two people have been injured in a shooting at a school in the US state of Georgia in the latest of gun violence in the country.
The incident took place at Price Middle School in southeast Atlanta on Thursday.
School officials said a 14-year-old student was transferred to Grady Memorial Hospital in downtown Atlanta after being shot in the head.
“The student was alert, conscious and breathing” while being transferred to the hospital, police said in a statement.
The second victim is a teacher, who had suffered minor injuries and was treated at the scene.
No details were released about the shooter and the weapon used.