The man was registered as a wild animal care giver. Each animal was registered, that's why poilice knew how many of what is missing. Retired circus animals, and idiots that keep dangerous exotic animals then find out the hard way they don't make good pets. The zoo's doesn't want them, it's a shame to kill them, and few programs can afford to spend the money or time to retrain an animal to be returned to the wild after being raised by humans, they don't know how to hunt for their own food, or be with their own kind.
A few people with enough land and a desire to help the animals take them in and provide care for them. They get volunteers to help with feeding, veterinary and cleaning the enclosures. The amount of food needed to sustain even a single tiger is outrageous, and the only income are usually donations.
This fellow was doing a public service, I don't know what horrible thing drove him to such a sad and deadly end, maybe the critters had nobody that cared enough to donate food so the guy got fed up, who knows. He released them, as to why...maybe he left a note, and maybe not. The government does regulate such permits, mostly they want to be sure the person knows how to care for the animal and can provide a decent life for them on some land and remote enough to not disturb the neighbors with noise or smells. They have animal control officers constantly making checks to be sure all is well.
Something went wrong, I don't know what, but it's the animals who are paying with their lives because they are too dangerous to be roaming free. Police and animal control will try and rehome as many as they can safely catch...but if they feel in danger they shot to kill. It's a sad, sad mess.
