"It found that he was shot by a high-powered gun, likely with a silencer on unless he was taken away from our residential area. He also had a broken leg so they thought he was stomped on," Walker told the Rotorua Daily Post as she held back tears yesterday.
Booboo was killed by a jacketed bullet, either on Friday night or Saturday morning.
At age 10, he learned to do high fives and sit on request.
"He was really friendly, very cuddly, was quite vocal. He would talk a lot," Walker said.
She said it had been a "really tough few days" since finding Booboo dumped.
"He would not have walked that far," Walker said.
"I have no idea why someone would do this. He did not wander. He was old and not a nuisance. Maybe the media stuff about cats and native birds prompted it.
"There are a lot of people hating on cats at the moment. The funny thing is when he caught birds they were never native."
Many of Walker's neighbours have children.
She said it was "quite disturbing" that Booboo was probably shot in her neighbourhood unless he was driven away, shot, and then dumped back near the houses.
"Anyone shooting in a residential area is just an idiot. I want them caught. We have a really good community and this is not the sort of person we want here."
Police confirmed they had a record of the complaint which has been "delegated to an officer to make inquiries".
Booboo's family encouraged anyone who had any information on his death to contact the police and quote the case number 180903/6729.
Rotorua SPCA manager Sue Kinsella said she could not comment on Booboo's death while police were investigating.