Lighthouse keeper's explanation (Spoilers)

The explanation why the lighthouse keeper leaves out food for the monster and doesn’t tell the police about it makes no sense. He discovered the monster living in the caves around the lighthouse so he sent his daughter to college to keep her safe and wouldn’t even allow her to come home for the holidays so he didn’t see her for 10 years. He said he fed the monster and didn’t tell the police because he was lonely and wanted to have another living being around - but if he had told the police they could have killed or captured the monster and he could have safely let his daughter come home from college so he wouldn’t have been lonely. Even if she only came home for the holidays he also had his dog to keep him company. It would certainly have been preferable to keeping a homicidal monster lurking around.