As Travis the chimp shook the police car, like a dinosaur rocking a jeep in Jurassic Park, officer Frank Chiafari took out his gun. “If he tries to get me out, I have no choice: I have to kill him,” Chiafari recalls. “He pulls around and he comes to my door and I’m looking at him – we’re looking at each other. He pulls the door right off and then he raises his hands up and he growls. All I see is these big teeth with blood dripping. He gave me a second and I tell people – I swear this is true – I didn’t hear it but it was like a connection and he said to me, please do it – like, I can’t take it any more.”

Chiafari did pull the trigger and kill the chimp, a pet of Sandra Herold, who had called 911 in terror after Travis mauled a family friend in Herold’s driveway in Stamford, Connecticut. The victim, Charla Nash, survived but lost her face, eyesight and hands. At first, emergency responders were not sure if she was a man or a woman.

This horror story – reminiscent of Gordy the chimp in Jordan Peele’s 2022 film Nope – is one of the darker strands in Chimp Crazy, a four-part docuseries about the private ownership of chimps. At its centre is exotic animal broker Tonia Haddix, who calls herself “the Dolly Parton of Chimps” and raises chimpanzees as her children.

The series is replete with jaw-dropping moments. A pet chimp sits with his owners watching the celebrated “dawn of man” opening of 2001: A Space Odyssey, in which ape-like hominids smash up bones. Trainer Pam Rosaire, who hails from a circus family, tells how she breastfed a premature chimp back to health; her husband recalls walking in to see a chimp at one breast and their infant daughter at the other. Another “monkey mom” shows off a huge closet of clothes she uses to dress her primate like a child.

Chimp Crazy is the work of Eric Goode, the director of Tiger King, one of the biggest TV sensations of the pandemic lockdowns when it was released on Netflix in March 2020. That series delved into the world of big cat conservationists and collectors, focusing on the intense rivalry between Joe Exotic and Carole Baskin.

Was Goode surprised that Tiger King turned into such a hit? He says via Zoom from a hotel in Los Angeles: “I obviously didn’t know it would land right when lockdown and Covid hit, so there were things that made it that much more successful. I never would have imagined it would have been that successful, because when I started, I never even thought about success. I thought I’d be filming for myself.”

Goode, 66, has deep experience in the animal world and, over the past 20 years, has travelled widely doing conservation work for endangered turtles and tortoises. His adventures with a camera led him not only to Tiger King but the so-called monkey moms, who tend to be mostly white women living in middle America.

Typically the moms are charmed by baby chimps – admittedly they are cute – but, once the animals pass puberty (earlier than in humans), they have to be managed and controlled, often with drugs, shock collars and the removal of canine teeth.

The series is built around Haddix, a former nurse with bleached curls, plumped lips and a fondness for tanning beds who is caring for seven captive chimps bred as talent for commercials, photo shoots and movies. She says in the film: “I love these chimps more than anything in the world, and I mean more than anything – more than my kids, more than anything.”

She has a special affection for Tonka, a 32-year-old chimp retired from a career in Hollywood, where he appeared in George of the Jungle, Babe: Pig in the City, and Buddy. She adds: “Tonka and I just found each other. It was meant to be. It was just natural and Tonka loved me as much as I love Tonka. It’s like your love for God.”

Haddix’s biological son confirms that he has become used to playing second fiddle to Tonka in his mother’s affections. Sitting on a upturned bucket with an air of resignation, he says on camera: “I’ve never seen her that passionate about anything in my life, ever, and that includes her own son.”

Goode reflects: “It’s complex. She possibly loves a chimpanzee more than her own children. It’s obsessive. It’s real: she absolutely loves this chimpanzee. But there’s probably also some – and I’m not a trained in this area – mental health issues that reside in a number of these women. Why they need so desperately to have that relationship versus a normal, loving relationship that we typically have.”

Haddix keeps Tonka caged in her basement, feeds him McDonald’s Happy Meals and, on her phone, shows him videos of his chimp relatives. She is blissfully ignorant – or in stubborn denial – about animal welfare concerns. Although it has gradually become more difficult to acquire a chimp in the US over the past 30 years, there are still no federal laws banning ownership.

What do the chimps themselves make of it all? Goode deadpans: “I can’t even tell you what my girlfriend’s thinking sometimes. I’d be insane to say I know what they’re thinking but there are certain tics that animals display when they’re experiencing extreme boredom.

“Tigers do a repetitive figure eight over and over and over and they wear down that part of the area they’re walking on out of sheer boredom. Chimpanzees typically do this rocking or they’ll lash out with violent bursts, showing dominance. Animals display this kind of extreme depression and boredom by doing things and each species does a different kind of tic.”

A chimp in a dark mood can be one of the most terrifying animals on earth, combining tremendous strength with daunting intelligence. When Goode was making Tiger King, he would often hear people say they would rather have a hundred tigers than one chimpanzee.

“I remember Joe Exotic, for example, had 200-plus tigers and then he had a couple of chimpanzees that were behind three layers of bars. He treated them as if they were prisoners because they’re so dangerous. He could go in with the tigers but he absolutely would not go in with the chimps.

“Chimpanzees, yes, they’re stronger than any human being but it’s their intelligence and the way they fight and go after you; they render you helpless; they bite off your fingers; they go for your genitals and your face. They are incredibly dangerous animals. They can figure out a combination lock so you have to lock them with multiple key locks because they’ll sit there all day and they’ll figure it out. They’re so incredibly smart.”

Chimp Crazy draws on home movies, TV news broadcasts and archival photos to duly delivers cautionary tales such as Travis, whose human-like upbringing with Sandra Herold and her husband Jerome included learning to steer a car and using a microwave oven. Jerome’s daughter Kerry DeBlasi says in the documentary: “Travis was like any other person in our family. He was just the one who couldn’t talk.”

Then, in an explosion of simian rage, Travis, 14 years old and weighing 200lbs , savaged Charla Nash, who later underwent a face transplant and appeared on The Oprah Winfrey Show. The film includes the ghastly, haunting shrieks of Sandra’s 911 call begging for help.

Sandra mourned the loss of Travis like her own child. But she did not learn from it. Goode notes: “That woman went out and bought another chimpanzee after something so horrific had happened to her friend, who is disfigured and blinded for the rest of her life and resides in a nursing home today. That chimp lived in Florida and she would go visit it.”

Making the film was far from straightforward. Goode was aware that Tiger King had made him notorious among exotic animal collectors, who would be unlikely to welcome him in with a camera. But he has years of experience going undercover at animal markets in south-east Asia and Madagascar, working with organisations such as Traffic and Interpol to combat the illegal wildlife trade.

He hired Dwayne Cunningham, a former circus clown who had worked with animals for decades, as a proxy director. Cunningham helped Goode get a foot in the door the Missouri Primate Foundation, a breeding compound run by Connie Casey, who had not given any media interviews for more than a decade.

Goode explains: “The hiring of what we called the proxy director was only to access this one chimpanzee breeding facility in Missouri. This woman was notorious and had been there for almost 50 years: effectively she had a puppy mill for chimps. She was breeding chimps and selling them on the open market in the US and we needed to access her.”

Cunningham did not land an interview with Casey but did discover Haddix, a volunteer living and working with chimps on the property. Goode continues: “We had to keep going with this deception, which was never our intention. We had to follow Tonia Haddix because we discovered that she would talk and that she was obsessed with chimps.

“That was a revelation, that was difficult and it was a relief when I finally was able to meet her and I would take the baton and film her from that point on. We built a relationship. It wasn’t our intention to have a proxy director. The question is, does the end justify the means in this?”

Goode also faced a familiar ethical dilemma for journalists: when to observe versus when to intervene. “When we discovered Tonka I had to call up primatologists and people that I knew to assure me that Tonka was OK for a period of time, because we were hoping that Tonia would lead us to more people that were keeping chimps and other apes in bad situations.”

The film follows twists and turns as, thanks to a whistleblower, the group People for the Ethical Treatment of Animals (Peta) investigates Haddix and slaps her with a lawsuit. Peta persuades a court that the Missouri Primate Foundation does not provide suitable living conditions for seven chimps and they should be moved to a sanctuary.

But when authorities try to relocate the great apes, Tonka is missing. Haddix falsely claims that Tonka died after a long illness (she even recruits a friend to dig up his own dead chimp to provide fake ashes). Peta is unconvinced and, ultimately, Haddix is forced to surrender Tonka to Save the Chimps, one of the biggest chimpanzee sanctuaries in the world.

As an animal devotee, Goode is sensitive to her loss but knows there is no alternative. “Every primatologist I talk to about this dilemma said to me, it doesn’t matter how much Tonia loved Tonka. Everything that Tonia could ever provide – the Happy Meals, the TV set, the air conditioning – for Tonka is trumped by being with other chimps, which is where Tonka is now. Chimpanzees, like us, are highly social, complex creatures and need to be with other chimpanzees, just as you need to be with other people.”

Chimp Crazy contains an unexpected cameo by British actor Alan Cumming, who starred alongside Tonka in the 1997 film Buddy and formed a bond with the chimp. He is vexed by Tonka’s apparent disappearance and adds $10,000 to a reward for information on the ape’s whereabouts. Cumming can relate to Haddix’s feelings but has come to understand what is in the chimp’s best interests.

Goode comments: “His views have evolved. The culture in the United States in general’s views have evolved over the last 20, 30 years. You can see Ringling Brothers and Barnum & Bailey Circus is out of [the animals] business. No longer can you use animals the same way you could in Hollywood films.

“Before I even stepped into the picture, Peta and law enforcement and animal rights groups were after Tonia. There may be a silver lining in this story for Tonia to maybe reinvent herself because history was not on her side, just like a number of the characters in Tiger King were already in trouble with the law before I came along.”

At the end of the final episode there is one more sting in the tail for Haddix, though she is unrepentant and chimp-obsessed as ever. She has watched Goode’s film before its release, laughing at some points and crying at others. He still feels empathy for her.

Goode muses: “It’s easy to vilify someone from a distance but if you spend time with someone – and in Tonia’s case she was very generous to let us into her world and even the parts of her world that were very intimate – you see things with more grey; it’s less black and white. There’s a lot of grey.

“Tonia’s a product of her environment. Obviously she can’t see or couldn’t see what you and I may see with the chimps in her care and how that was probably a very one-sided love affair.”