Instead, a prayer posted by Rachel Held Evans on her blog seems appropriate:
Gracious and loving God,
You watch the ways of all of us
and the utter destruction of which our hands are capable.
We implore you to weave goodness and grace
in the lives of those destroyed by senseless violence.
Surround those whose lives are shattered with a sense of your present love.
Wrap them in the warm quilt of your compassion.
Though they are lost in grief,
May they find you and be comforted.