As our story begins, the very lovely Mary (Warrene Ott) is mauled by a tiger (see above) in the middle of L.A., while walking home. Apparently Mary was snooping around too much at her job at Conrad's Animal Kingdom. Michael Conrad (Gough) runs this zoo and he is very protective of his animals. As L.A. grows, the city counsel is re-zoning major portions of it so more residential homes can be built. When Conrad is approached by a seedy developer who tries to blackmail him into selling his zoo to him, Conrad visits him at his home with a lion. The police are baffled as now they have two wild animal attacks in L.A. Meanwhile, Edna (Cooper) is Conrad's abused wife. She has an outstanding chimp show which would horrify the modern viewer. You see, the act culminates with a chimp lighting and smoking a cigarette. The zoo features big cats (a lion, tiger, two cheetahs, and a black leopard). Claiming to love the animals more than humans, Conrad in reality is exploiting them to his evil ends. When one of his workers abuses the tiger, the tiger claws him. The unfortunate miscreant then shoots the tiger to death, and is then thrown to the lion by Conrad. What happens next is most eerie....a night time funeral for the tiger attended by the Conrads', their mute zoo hand, and the other large cats.
Depressed at his loss, Conrad goes to "church." Not your ordinary church. Church of "The True Believers" is a bunch of animal worshipers who do a ceremony to put the deceased tiger's soul into a cub (see above). His so-called love for animals is not matched with love for Edna. In some hard to watch scenes, Conrad physically abuses Edna. Edna reaches her tipping point and talks with Jenny Brooks (Virginia Grey) an agent and accepts an offer to bring her chimp act to the country's largest circus. Unfortunately for Jenny, Conrad is not keen on letting his wife leave, so as Jenny drives into her driveway, she is met by a gorilla (see below). The LAPD now have three murders, which they know about, and put all their resources on the case. Kudos to the LAPD who state that the animals are not to blame and are hunting for a deranged animal trainer. In fact, at no time in "Black Zoo" do we see the animals as monsters, as Conrad emerges as a demented fiend.
As the LAPD accumulate more clues, Edna realizes what is going on. Will Edna be able to escape her mad husband and his cats? What is the secret relationship between Conrad and his mute employee? Gough is terrific as a mad fiend. He socializes with his cats in his study while playing his pipe organ. Realizing that the modernization of L.A. does not have room for a family owned zoo, Conrad starts coming apart. Unfortunately for some of the citizens, he uses a very unique weapon (his animals) to strike out. See "Black Zoo." This is an effective horror film which avoids painting the animals as monsters, instead focuses on an abusive handler.