Having grown accustomed to his freedom in The Jungle, the “humanized” chimp needed too much supervision and went berserk when he was put in his cage. … When Jerry became more and more impossible, Dutton took Jerry into a nearby orange grove and gave him a shovel. “I had him dig a deep hole,” Dutton said. “When he was finished, I told him to jump inside. Then a policeman friend shot him in the head.” 

“Dutton” is Jack Dutton, described as an “eccentric millionaire and showman.” He built up a private menagerie, then put it on display as an Anaheim tourist attraction called The Jungle. Jerry the chimp was the attraction’s top-billed star, “The World’s Most Human Chimpanzee.” 
Dutton and his wife had taken Jerry from the jungle, the real jungle, and “raised him as their child,” says my source, the fine coffee-table book Southern California in the ’50s (compiled and written by Charles Phoenix, designed by Kathy Kikkert). The book continues: “Within a few months he was toilet trained, sat at the dinner table, dressed himself … Locals, tourists, schoolchildren and church groups enjoyed Jerry’s antics as he played with Sunny the bear or swam with the ducks in the pond.”
But in just a few years, everything fell apart. Disneyland opened, neighbors sued because they thought the animals were dangerous, Dutton’s wife eloped with his lawyer. And Jerry fritzed out. Dutton had to hire people to look after Jerry around the clock. Then he tried giving Jerry away to zoos — no good.
Then the shovel, the grave. The single bullet. The role for Bill Murray if some indy wiseacre makes this business into a film. (I see Murray in shorts and safari jacket, bush cap riding the back of his head, the strap under his chin, his face puckering as the tears squeeze out.)
Thanks to The Inkwell Collector for recommending Southern California in the ’50s.