The girlfriend of an off-duty police officer has been charged with shooting him to death inside his Philadelphia-area home.

Authorities in Delaware County charged 27-year-old Tyaina Finch of Glenolden with first- and third-degree murder in the death of 26-year-old Mark Hudson in Darby Township on Saturday.

Officials say Hudson had worked part-time for the Darby Borough police department for four years.

Authorities allege in a criminal complaint that Finch at first said the shooting was accidental but later said she fired in self-defense after being attacked.

A day before being charged with murder, Finch was arrested Monday on threat and assault charges stemming from a dispute last summer during which authorities allege she threatened Hudson with a knife.

The county public defender's office couldn't be reached for comment late Tuesday.