Police have charged a pregnant 16-year-old girl in the stabbing death of the 19-year-old father of her unborn child.

Police said they were called to an apartment in the South Boston neighborhood about 2:45 a.m. Sunday, where they found Rocky Ham (search) of the Dorchester wounded in the chest. He was taken to Boston Medical Center (search), where he later died about 90 minutes later.

The girl, who is three weeks from her due date, was arrested and charged with the killing. She was due to be arraigned Monday in South Boston District Court (search).

Police did not release her name because she is a minor.

"The evidence suggests the victim and defendant were in a serious dating relationship, and early (Sunday) morning they became involved in an argument, and during that argument the defendant stabbed the victim," said Suffolk District Attorney spokesman David Procopio. "The cause of the argument is still under investigation."

Neighbors said Ham and his girlfriend were part of an extended family that had moved into the apartment on Orton Marotta Way a few months ago.

Besides the couple, the girl's parents and two children lived in the apartment, neighbors said.