Boyfriend, 19, held in slaying of pregnant S. Phila. woman

Based on the couple's history, Fitzpatrick, 19, was a suspect from the outset, Clark said, and he was arrested Thursday after being questioned by detectives. He was expected to be formally charged Thursday night.

"They had been arguing over the last 24-hour period," Clark said. "He was upset with the fact she was pregnant with his baby, and killed her as a result."

Clark said the couple had a history of domestic disputes for which cops were called to Gillespie's home.

"[They] had a rough relationship," he said.

Bill Boyle, a neighbor of Gillespie's, said he and his wife, who both work nights, were unloading cleaning supplies for their business on the block early Thursday when Gillespie's mother bolted out of her two-story, red-brick rowhouse screaming, " 'My daughter's dead! My daughter's dead!' "

Within minutes, police cruisers swarmed the block, as neighbors gathered and detectives began questioning the family and hunting for evidence.

Neighbors said Gillespie had a preschool-age daughter and an 8-year-old son, and told them she was six months pregnant.

"It's such a shock to hear," said Angela Holton, 24, a friend who grew up with Gillespie, said of the slaying. "I know they had a lot of stuff going on in the family."