By Cole Hill (staff@latinospost.com) | First Posted: Apr 09, 2013 12:03 PM EDT

It just took a matter of seconds for a 4-year-old boy to pick up a loaded handgun Saturday night, but by the time anyone realized what was happening, it was already too late. The toddler aimed the firearm at a Tennessee deputy's wife and fatally shot her in what police are calling a "tragic accident."

Wilson County Sheriff's Deputy, 51-year-old Daniel Fanning, was having a cookout at his Lebanon, Tenn. home over the weekend with family and friends when he decided the show off a new rifle to a male relative in his bedroom. The elementary school resource officer went to a locked gun cabinet to retrieve the firearm, removing a loaded handgun and placing it on the bed in order to reach the rifle. While the handgun was only on the bed "for a moment," the time still proved to be too long. 

Unbeknownst to Fanning or his relative, the deputy's wife, 48-year-old Josephine walked in the room with his 4-year-old nephew trailing in behind her. The young boy grabbed the handgun and fired once, shooting Josephine Fanning. The deputy's wife was pronounced dead at the couple's home. 

"He was actually showing another person that was there at the house some of his weapons he had locked in a secure gun safe," Sheriff Robert Bryan explained to WTVF-TV.

"Split second, we're talking about seconds for that kid to walk in that room ... grab that gun and it goes off," Sheriff Bryan said.

The Sheriff said deputy Fanning was careful about securing his firearms in his home, and it looks to be horrifying accident.

"He did not normally have small kids at his house, and his guns were locked prior to coming out. I don't want the perception that guns were everywhere. He took all the precautions, he's a trained law enforcement officer, trains with weapons all the time," said Sheriff Bryan.

The Tennessee Bureau of Investigation has been called in to handle the case by prosecutors to determine if any adults may have broken the law. The TBI said the gun used in the shooting was not Fanning's service weapon. Because a child was involved in the incident, the Tennessee Department of Children's Services has also been asked to investigate.

According to the U.S. Centers for Disease Control and Prevention, Tennessee has the sixth-highest mortality rate from accidental shootings in the nation.