Here's my stab at a mission statement. It's pretty similiar to what you and Sara developed. I also (tried) to come up with some objectives for us.
The mission statement would be more for the public, to state what we're about. The objectives would be more for us, to keep us focussed. Just a rough draft, so add, change or delete as needed.
Our goal is to be a voice for domestic animals and seek justice on their behalf by working for harsher punishments for those who abuse them. We aim to increase public awareness of the frequency of these heinous crimes and raise consciousness of the correlation between animal abuse and violent behavior.
1)\t We will seek change to the laws (local, state & federal?) related to the punishment of those who engage in the abuse of domestic animals.
2)\t We will work with humane society investigators, law enforcement officials and prosecutors to obtain information pertinent to abuse cases in our areas of residence.
3)\tWe will strive to educate the general public of the prevelance of such crimes.
4)\tWe will encourage others to join in our efforts to seek justice for domestic animals that have been abused.