Lund said she and her husband were inside their home watching TV when they heard a disturbance in the garage.
Lund, who has five dogs of her own, said she was heartbroken from the death of the actress' dog.
"My heart is broken. I'm really sorry that the dog died," she said.
"I'm still coming to terms with all of this, as you can imagine. We didn't even know we killed a dog. To find out we killed a dog that belonged to a high profile person, I'm in shock," Lund said.
The caretaker told the Thurston County Sheriff's Office that she had went horseback riding with a few dogs and at the end of the road, the dogs took off toward the sound of other dogs barking at an adjacent property. Eventually, the caretaker realized that one of the dogs had not returned and later found Mozart dead on the Hayek's property.
A local veterinarian had determined that the lead pellet nicked an artery, causing Mozart to internally bleed out.
"I haven't posted for a week as I been mourning the death of my dog, Mozart who I personally delivered out of his mother's womb. He was found dead in my ranch last Friday with a shot close to his heart. I am hoping that the Washington State authorities do justice to this wonderful dog whom in 9 years never bit or attacked anyone. He loved his territory and never strayed away...he was the most loving and loyal companion. He didn't deserve a slow and painful death. #doglover #animalrights #dog #dogoftheday #rip #delivery #washingtonstateauthorities"