Kinsler Davis accidentally shot himself in his home in Corsicana Wednesday at about 8:45 p.m., The Dallas Morning News reported.
The toddler was rushed to Navarro Regional Hospital and then airlifted to Children's Medical Center in Dallas, where he was pronounced dead about 11 p.m., police said.
Kinsler's father told police his son found the gun in a bedroom. The father was in an adjacent walk-in closet when the gun fired.
Police Chief Randy Bratton said the incident seems to have been an accident, but police are still investigating.
"When the investigation is concluded it will be referred to the District Attorney's Office to review for consideration of criminal charges," Bratton said in a statement.