Police in Tennessee are investigating how a 3-year-old boy managed to shoot his 18-month-old brother in the head with a handgun.

The incident occurred Tuesday afternoon in Coffee County when the 1-year-old was struck by a bullet fired from a .25-caliber pistol at a home in Hillsboro, not far from Manchester. According to Coffee County Sheriff Steve Graves, the baby was awake and alert when first responders arrived on the scene. He was then taken to Vanderbilt University Medical Center in Nashville. The hospital has not released his condition, however.

Sgt. Danny Ferrell told The Associated Press that investigators are working to determine how the 3-year-old got access to the weapon in the first place.

"We've still got interviews to determine how the child came about getting the gun," said Sheriff Steve Graves, according to Reuters. "There's no doubt the 3-year-old shouldn't have had access to it."

Sheriff Graves added that the child's parents would undergo interrogation on Wednesday.

A similar incident happened last month when a 3-year-old boy shot and wounded his father and pregnant mother inside of a New Mexico motel room. The incident took place in northeast Albuquerque after the toddler discovered his mother's new 9 mm pistol as he was searching for an iPad in her purse. That's when he fired one shot that struck his father, Justin Reynolds, in the buttocks and his mother, Monique Villescas, in the shoulder.

Police arrived on the scene at the America's Best Value Inn and both parents where then taken to the hospital to be treated for non-life-threatening injuries, Albuquerque Police Department Officer Simon Drobik said, according to Reuters.

Reynolds told NBC News station KOB he and his girlfriend were just about to order pizza when he heard a gunshot.

"The next minute I realized my girlfriend was bleeding," he said. "Then I sat down and realized I was shot, too." In response, Reynolds called 911 and grabbed towels to try to stop Villescas' bleeding.

"I just took action right away," he said. "I was more worried about my girlfriend than myself and anything else that was going on. And my son because I didn't know if he had shot himself or not. He was shocked and crying. It was traumatizing."