The bird was found dead after being shot in the head with a ball bearing.
The Swan Sanctuary is calling for tighter catapult laws, with police officer Ellie Vesey-Thompson urging they be treated like knives.
A petition launched by Shepperton swan sanctuary volunteer, Danni Rogers, has gathered more than 20,000 signatures calling for action.
Volunteers Tiff Jones and Wendy Hermon tell us more.
