A jury has awarded more than $38.5 million in punitive damages to the families of two women killed by a co-worker at a Philadelphia plant 4½ years ago.

The decision came Monday in the suit filed against U.S. Security Associates Inc. of Georgia in the September 2010 shooting deaths at the Kraft Foods plant.

A separate panel earlier ordered the firm to pay more than $8 million in compensatory damages.

Forty-eight-year-old Yvonne Hiller is serving two life terms in the slayings.

Attorneys for the two families said security guards failed to protect employees.

But the company vowed an appeal, saying there was insufficient evidence for punitive damages, and said its personnel "acted with courage in the face of a direct threat to their own lives."