Whether or not he is innocent/guilty/crazy/sane is to be determined but one thing about the dogs - the first thing police do is kill any dog that looks like it could attack them, they don't have to justify it so it's fun target practice for them. Special ops that don't want any alert by gunfire or barking would definitely poison the dogs with tainted meat, etc.
So that part is not hard to believe. There are other aspects though that are worse. It's a series of poor, dramatic choices.
I'm actually not sure about that. If they need quiet, they'd shoot the dog quietly - but apparently the dogs had not yet all died by the time the interview was held, so they were alive far, far longer than could possibly be of any benefit to a special ops team.
More likely that a neighbor did it, sad as it is. Maybe the guy that got shot, maybe somebody else who got sick of a pack of wild dogs trying to attack them for using a public beach. It's one thing to "love dogs" and another to tolerate a dangerous pack of animals in your neighborhood that have been spoiled by a paranoid nutcase.
With a silencer, I guess. What do I know? I've never shot anything nor do I plan to - but it seems a silencer would be quieter than a dog that was still dying of poison two days later.
I am no dog trainer, but I've lived with them all my life. The dog would needs trust in order to take food from a stranger, even if you threw it to them at a distance. Some dogs are more trusting than others. And some dogs are fussy eaters too. They may not even be hungry and decide to bury it for later.
Basically, if you want it dead, its simpler to shoot it. Less elaborate planning required.
So that part is not hard to believe. There are other aspects though that are worse. It's a series of poor, dramatic choices.