Evil Clowns?

I read a short story when I was younger, and although I cannot remember all the details, it involved a late teenage boy who began to see clowns every where that bad things happened. The clowns were shabby, dressed mainly in black and a sinister air about them. It happened that a car hit a pedestrian and killed he in front of the young man. He appeared to be the only one of a Crowd of onlookers who saw one of these unsavory clowns push the woman into the path of the oncoming vehicle.

By his reaction, the clowns that flocked to the scene could tell that the teen could see them. They began to follow him everywhere, despite his frantic attempts to warn others of the danger and to escape himself. Finally after seeing the Black Clowns perpetrate several more murders that appeared to others as unfortunate mishaps, he went home to spend the night.

Arriving late, he went to his Parent's bedroom determined to wake them and warn them of the Danger. When he reached to wake his Father and Mother up, he saw that it was not them at all, but two of the evil, dirty, unkempt clowns who apparently had killed his Parents and were attempting to take their place.

Knowing he had to act, he ran into the Kitchen, found a very large Knife and repeatedly stabbed the clowns until he was sure they were dead.

Exhausted , he then went to sleep, only to wake up the next morning, overcome with fear. He lightly dialed 911 for the Police and told them what had occurred.

The next scene is the Kicker! When the Police get there, all they see is the horribly bloodied bed with his Parent's butchered Corpses.

Stunned , he is taking in Custody by the Police for the Murder of his Parents. As he is being led to the Police Car in Shackles. On the way to the car he notices all around the car..are the Black Clowns.....laughing silently, at Him!

So did he really have the gift to see this Malevolent Clowns or was he insane?