A 3-year-old boy was shot and killed inside a Columbia, Maryland, home Monday in what Howard County police said was an apparent accident.

The shooting happened inside a home on Harpers Farm Road. Detectives have determined a handgun was left unsecured inside the residence. Police are still trying to figure out if the gunshot was self-inflicted or fired by someone else inside the home.

The boy’s 5-year-old brother and parents were home when the shooting happened. Police said they do not believe anyone else was involved and they don’t see any indications of foul play.

Police have not yet filed any charges connected to the shooting but will continue their investigation.

Last month, a four-year-old girl accidentally shot and wounded herself in Prince George’s County after finding a gun under a bed during a game of hide-and-seek, police said. Days later, another young child — a 3-year-old girl — accidentally shot herself in neighboring Montgomery County. Both children were expected to recover. Charges were filed in both those shootings.