By Tony Hanson

PHILADELPHIA (CBS) — With her father’s life and freedom on the line, a young woman testified today that her father was being attacked outside their Port Richmond home when he shot and killed a 21-year-old man more than two years ago.

Felicia Tepper, 19, told the jury that her father, Frank Tepper, an off-duty Philadelphia police officer, had tried to be a peacemaker during a confrontation outside their home.

She testified that he identified himself as a Philadelphia police officer but was attacked anyway — jumped, she says, by a large group of young men who were punching him in the face.

Then, she says, she heard the gunshot.

She broke down and cried on the witness stand.  Her father, at the defense table, also wiped away tears.

But the prosecution says there was no attack and no threat to Tepper when he fired.  And friends of the victim have testified to that effect.

Tepper is charged with murdering William Panas during a neighborhood dispute in 2009 (see related story).