As the early birds on Genesee Drive in the Northeast were preparing to open their Christmas presents yesterday morning, homicide investigators were setting up a crime scene at the end of the block, where police say Helen Wollaver received a deadly gift from her live-in boyfriend - a butcher knife to the stomach.

"We believe he just snapped," Homicide Sgt. Bob Wilkins said of the 47-year-old man who was in custody last night but hadn't yet been charged. "There appeared to be a struggle inside."

Police responded at about 7:15 a.m. to the rowhouse on Genesee Drive near Nanton Drive, where Wollaver, 43, a Kensington native, had been stabbed once in the abdomen with a kitchen knife. She was pronounced dead at the scene.

"All I know is that he stabbed her," said Wollaver's brother, Jim. "The scumbag should die."

Wollaver did not have a restraining order against her boyfriend, and police had not been called to the house before, according to Wilkins, but Jim Wollaver said he had a violent streak.

"She had it rough for a while; then she just started getting things together," Jim Wollaver said of his sister, who worked at Franklin Mills. "She moved to a new house and got a new job and all - and then this happens."

"That's a Merry Christmas, huh? Why today?" neighbor Bob Capriotti asked.

Capriotti, like the rest of the block's residents, was stunned to hear that a homicide had occurred in his seemingly safe section of Northeast Philadelphia.

Jenn Clementson, who lives across the street from Wollaver, said, "I've lived here 27 years and nothing like this has ever happened . It's crazy."

Capriotti said that the couple had moved into the house recently and that few on the block knew them by name. He hadn't noticed any "warning signs" that their relationship had soured.

"But you never know what's happening internally with families," he said.

Clementson said that the neighborhood, across the street from Franklin Mills, is safe, especially because several cops live on the street.

By early afternoon, police had left the scene, and residents retreated to their homes.

"I don't understand why anyone would do that," Clementson said. "It's sad that it happened today, to see that stuff on Christmas morning. People just snap." *