Tributes last week remembered him as the photographer who took the last photos of Robert F. Kennedy as the senator lay dying on the floor of a Californian hotel. But Bill Eppridge, who died on October 3rd, was a photographic icon long before that fateful night in 1968. Throughout the 60s, Eppridge documented for Life magazine the fast-changing America — he was there when the Beatles first came to New York; he photographed Barbara Streisand washing her clothes in a tub; he saw an emotional fraught funeral for a Civil Rights leader murdered by the Klan.

But for this author at least his most powerful work was the photoessay on heroin addicts in New York City which appeared in Life magazine in February 1965. Eppridge and James Mills, associate editor at Life who wrote the accompanying article, spent months trailing and living with two addicts who described themselves as “animals in a world no one knows.” That touching photo essay, gritty and raw well before the words became overused in photographic context, won the 1964 Headliner Award. That story later inspired the motion picture, ‘Panic in Needle Park’ starring Al Pacino and Kitty Winn as John and Karen, “two lives lost to heroin,” in LIFE’s powerful words. [Further photos on Life website].

Here is Eppridge, remembering the assignment:

The writer, Jim Mills, and I started doing research on the heroin culture that had crossed over from subcultures and was quite seriously affecting the white middle classes. We spent three months learning everything we could about it. It took us that long to find a couple, after contacting every agency we could. When we found them, we had to persuade them to do it for free; we couldn’t have paid them – it would just support their habit. I went and lived with them for three months, and tried to be invisible. I’ve been skinny and gaunt all my life, so I fitted in with that society. It got to the point when they just ignored me and didn’t care whether I was there or not. As a matter of fact, I got stopped by the cops more than they did. They wanted to know where I got the cameras.

Often we would lead a story with a question rather than a statement. There is a statement here, but it asks a question… ‘We are animals in a world no one knows’: What is the world? How are the people like animals, they look like a normal couple, crossing the street? It brings the reader in. In the next spread you see who they are: heroin addicts. We did not show the needle very often; we had to be aware of our readership, so we didn’t want to show a lot of gore.

Karen came from a very fine family, on Long Island, but to make money to support her habit, she wasa prostitute. She was a beautiful woman. The police referred to her as the actress. She could change her looks at a whim, but when she did too many drugs, she started to look bad. John came from a very fine family in New Jersey, but to make money, he stole, boosted from cabs – he was a petty thief. Karen found that she couldn’t support her habit anymore, so she checked herself into a hospital, and was able to cut back to a habit that was affordable. I don’t think that’s possible today. I went in with them and photographed things as they happened. None of this was ever set up, I just lived with them and I waited until things happened.

They were on the street looking for a dealer; I looked over their shoulder and there was a gentleman standing there who looked like he didn’t belong. It was a cop, an undercover narc. He and his buddy came along, they spotted Karen and John were addicts, and they proceeded to search them. John was put in jail. I went to the judge and asked if we could photograph him in jail. I don’t know if it’s possible to have that access today. So, John’s in jail and Karen’s got to go and get drugs. She goes to see a dealer.

I was sitting in the lobby of the hotel, waiting for her to come down, and I got a phone call. It was Karen, she said, “You’d better come up here, we got a problem”. Her dealer had overdosed. The guy could have died. It was a big dilemma; should I call the police or should I photograph it? I asked Karen how she felt about it and she said she could bring him round. So I took her word for it and didn’t call 911. And she brought him around. I constantly faced situations that bordered on illegal. It was hard having to make these kinds of decisions, but I think I made the right ones most of the time.

One of the things we highlighted was that this was not a physical addiction as much as a psychological problem. We also said that it was difficult, if not perhaps impossible, to totally deal with this problem. Those addicts still exist in one form or another.