Happy death day!

Some people swore that the house was haunted. Glasses upon the shelves would fall and break, dishes would rattle and quake. Blossoming flowers would shrivel and die, as animals went missing, only to be found in a corner stiff as a board. Faces would appear in the windows, only to vanish when given a second look. Nobody dared to live there, for they all knew what had happened inside. A family of six had once lived there happily and serene. For eight years they enjoyed their lives within the house, having not a clue as to what was going to happen to them on their youngest son's twelfth birthday. A neighbor of theirs, always quiet and discreet, decided to come over on that day to meet the family. In-laws, cousins, grandmothers and grandfathers were all pilled inside. They talked and laughed, discussing many a things. One ring of the doorbell and they all fell quiet, no one had rung it to be invited in; they had all just walked in with a warm smile. There were no windows upon the door, and the mother didn't bother with the peep-hole, figuring it was one of the relatives being polite. Their neighbor barged in, carrying a machine gun in his hands, and shot the mother with a wicked grin. He then turned to the rest of the party and began firing without a rest. Women screamed in pain and horror as the men tried to shield the ones they loved; but the bullets from the gun were far to fast for the men to compete with. It only took three minutes for all of the people within the house to be pelted down by the numerous bullets. When everyone was dead, their neighbor/killer stepped over their bodies and opened up their fridge door; taking out the birthday cake for the, now dead, twelve year old. Across the top it said in blue letter, Happy 12th Birthday Jeremy! Underneath was a smiley face accompanied by blue and green balloons. It was a beautiful cake, and their neighbor smiled down at it in a haunting way.
"Happy Birthday to you, Happy Birthday to you, Happy Birthday dear Jeremy, Happy Birthday to you." he whispered with the ghost of a smile across his lips.
He took and swiped his finger across the front of the cake before sticking it into his mouth and swallowing the creamy icing. Then he placed the cake back into the fridge, closed it and didn't even bother walking around the bodies as he left the house and went back to his own. A Chevy was parked out in front of his house, packed with belongings of his. It only took one minute for him to place the remaining pieces of his property into the vehicle before driving out of the driveway and heading for the end of town.
It took three hours for the bodies to be found, and by that time the police didn't know where the culprit was and they knew they were already to late to stop him. As the cops discussed the fact that they wouldn't be able to stop him, the windows shook and the TV exploded. Nothing was ever the same again after that.