Like most inquisitive 4-year-olds, Dyshon Boyd was curious about a lot of things.

But it wasn't his curiosity that killed him Monday, police said.

Instead, the city's top cop said, it was his father's fatal mistake of leaving his loaded .40-caliber handgun - which, as a convicted felon, he should not have had - in the room with his son, who then used it to shoot himself in the neck inside the boy's grandmother's Southwest Philadelphia rowhouse.

For his negligence, the boy's father, Djuan Boyd, who turned 24 last Wednesday, is going to have to live with two things, said Police Commissioner Sylvester Johnson: criminal charges and the loss of his child because of his doings.

Johnson said Boyd, of the Haddington section of West Philly, was charged yesterday with various offenses, including involuntary manslaughter and endangering the welfare of a child.

"You have to remember when you have these guns, especially with children, you should never leave them in an unprotected area, under no circumstances," Johnson said at police headquarters yesterday.

Dyshon, a fun-loving toddler who family members called "Pooh Bear," shot himself once in the throat about 4:50 p.m. Monday inside his grandmother's and great-grandmother's two-story rowhouse.

The tot was pronounced dead about 5:30 p.m. at Children's Hospital of Philadelphia.

On the night of the shooting, the father was described by family members and neighbors near the home on Salford Street near Chester as "a great father."

Which he might be, but, as Johnson pointed out, because of his criminal record Boyd couldn't lawfully possess the gun he was carrying and which his son used to accidentally shoot himself.

Boyd has been arrested almost every year since 2003, the year in which he was sentenced to 6 to 12 months for drug possession.

The following year, he pleaded guilty to simple assault and carrying a gun without a license. He was sentenced to 11 to 23 months for that crime, according to court records.

He had a recent court hearing for a drug-related crime that occurred earlier this year.

That case is listed for trial.

But despite his rap sheet, cops said Boyd was remorseful when he showed them where he tried to dispose of the gun.

As of last night, cops said they hadn't found the gun's magazine.

At sunset last night, Michelle Green, who said she was a cousin of Dyshon's, hugged two unidentified women who brought condolence cards.

As she thanked them, the women said they would pray for the family.

"We're not ready to talk," Green said of the family as a relative nearby dabbed her teary eyes.

Dyshon was a lively child with a bright smile, said one relative.

He loved pizza and cartoons on Nickelodeon and had a large sneaker collection.

He is also one of the city's youngest victims of gun violence, police said.

"Eighty-five percent of homicides in the city are by handgun," Johnson said, although this case is offically classified as an accidental death.

Boyd stashed his handgun in his coat and left it in one of the upstairs bedrooms and went downstairs to play cards with the child's mother, grandmother and an aunt, Johnson said.

Dyshon, who was upstairs, found it, police said, and family members then heard the shot.

The family had never been investigated by the Department of Human Services.

And they won't be investigated in the accidental death of the toddler, according to Alicia Taylor, communications director for the Department of Human Services.

Johnson said he went to the hospital that night and saw the pain of Dyshon's family and said the police department is "very upset about this just like with any other person who's lost their life here in the city of Philadelphia.

"We will not be able to bring that child back," Johnson said, "but we can use [this incident] as an example that you can never leave your guns unprotected at any time nowhere here in the city of Philadelphia." *