Tripp Shaw died last week from head injuries sustained after the Jan. 19 incident. Tyler Shaw, his father, was also struck by the bullet fired from a gun concealed in his pants, according to the Monroe County Sheriff's Office.
Police said that while the two were playing, the Glock semi-automatic handgun fell and one shot was fired -- striking them both in the head.
Both victims were taken to IU Health Bloomington Hospital. The 4-year-old was transferred to Riley Hospital for Children in Indianapolis.
Sheriff Brad Swain said the boy's mother and 2-year-old sister were in the house at the time, according to the Indianapolis Star. He told the paper the weapon was sent to be tested for defects that could have caused it to fire unexpectedly.
The case remains under investigation and no charges have been filed, according to Fox 59.
A GoFundMe page has been set up to support the family called #ShawStrong.