TWO MINUTES TALKING to David Simon and certain things are clear: He never takes credit for anything if he can share it with a co-conspirator; and he definitely doesn't take compliments well.

The compliments part is a particular shame when you're being interviewed by an outright Wire junkie and all-around Simon fan - it's going to make the conversation awkward because, like it or not, I tell David Simon the following:

a) The Wire, the five-season masterpiece he created for HBO, is the single drama in the history of television that crosses the line from entertainment to art. (There are other shows, he tells me.)

b) Generation Kill, his seven-part mini series, strikes the impossible balance between being utterly patriotic and the most damning dramatisation of America's invasion of Iraq.

c) That he's a man (and this just makes Simon recoil) with a giant moral compass stuck in him.

When I met with Simon in the Baltimore row house he uses as an office, I'd just read Homicide: A Year on the Killing Streets. For The Wire fanatic, stumbling upon Homicide is like showing up at a Lord of the Rings convention in your Frodo costume and discovering that those movies you love are based on a book.

The story - now published in the UK for the first time - chronicles a year Simon spent shadowing Baltimore's homicide police in 1988. It's a page-turner of a police procedural, a character study, a history lesson, and an excellent guide of what not to do if you're plotting the perfect murder.

It is also the birth of David Simon's Baltimore. Simon can't be any more adamant about the fact that his Baltimore isn't all of America, it's not even all of Baltimore. We talk a lot about the city and its portrayal in The Wire.

“I don't mean to sound like I'm from the Greater Baltimore Committee,” he says, “but I live here, and I wouldn't live here now if it wasn't a viable city in certain fundamental ways. The Wire is dystopic because it's about the part of America that got left behind. We are a society with some dramatic schisms and it's a drama wholly set in a part of the country that has been economically, soci-ally and politically isolated for generations now. That is not to say it's not accurate. It is accurate. I mean it's fiction. But it's accurate in a way that fiction tries to be.”

David Simon is a big, solid guy. Sunk into the corner of a couch in the windowless room where we chat, he talks straight, full of passion, while maintaining a sense of utter ease. It seems like just the personality you'd need if you wanted a squad of completely fraternal, jaded and wholly dedicated homicide cops to let you become a part of their lives.

In Homicide, Simon writes: “In the minds of Baltimore's prosecutors and detectives, at least, television has utterly shattered the notion of a thinking jury ...” I want to know if he really believes television has nega-tively affected justice.

“My whole take on police procedurals is that they're desensitising us to the realities. Look, the number of people killed on all three versions of Law & Order in any given year is more than the number of people actually killed in Manhattan, total. And virtually all of them are white.

“Why are the victims always white and affluent? Because it's almost a wilful avoidance, by American culture, of looking at the real nature of violence. Victims are black and brown; they don't have money; they are living in an alternate America that has been discarded. There is no barbed wire around West Baltimore, but there might as well be. And those are the victims. Your chances of being killed in Baltimore if you're white are the same as being killed in Omaha, Nebraska if you're white.

“Why do I know that?” Simon asks. “Because I actually did the stats.”

No matter how much blood is shed in The Wire, it is still a love story to Baltimore. “It is,” Simon says. “But by a very clear-eyed and somewhat conflicted lover.”

As for portraying all that violence, here is Simon's take on that: “There are 741 television shows about the healthy, viable, economically sound America, that portion of America that some of us inhabit. There is one television drama that undertakes to depict the other America, the neglected, dystopic, utterly-disconnected- from-the-external-economy America. Are you telling me it's one too many? Who the fuck is telling me it's one too many?”

Late in the book there is a scene where Simon gets into a detective's head. The man has just witnessed the autopsy of a raped-and-murdered little boy. Simon reports the detective's internal struggle this way: “It ain't my kid, he tries to tell himself ... It ain't nothing to me.” In that instance, Simon writes, the homicide detective's “standard defense” just “isn't quite enough”.

But if the cop has nowhere to put this nightmare, where does the man standing next to him with the notebook put it?

“I think I started putting it in the same place the detectives do. Which is, I can remember with great precision the first murder scene I went to,” he says. “I can remember everything about Kenny Vines,” a drug dealer found murdered at the start of the book. “He's fixed in my mind. Kenny Vines and me are going to the grave together.” Simon must mean it. Because it's 20 years later and the name is right there, and I can practically see the body in front of his eyes.

If that first murder stays sharp, time can dull the edges on other crimes. The man who plays the Deacon in The Wire, Little Melvin Williams, was “one of the biggest drug dealers in the history of America”. Ed Burns, Simon's writing partner and a retired Baltimore homicide detective, “locked him up in '84” on a wiretap case. A twentysomething Simon interviewed Melvin in prison for a series of stories.

Then, in 2004, the three of them, Burns, Williams and Simon, are having lunch together in Little Italy. It's just the kind of improbability that Simon is always acknowledging as key to the success of the show. As they finished dessert, Melvin gave Simon a card with his cellphone number on it. “And Ed just said, ‘What I wouldn't have given for that 20 years ago'.”

Twenty years later, the cop, the criminal and the reporter are a long way from where they started. The reporter is no longer the invisible kid riding with the homicide police. He's now a big-time writer and producer with a fierce fan base.

When Simon and I run out for a cup of coffee, I can feel the we're-not-going-to-notice-you celebrity around him. It's Baltimore - they know whose coffee they're pouring.

Simon would prefer his anonymity back, but after five years of on-air promos, that's pretty much gone. He gets recognised, finds scripts dropped at his door. Strangers call out: “Are you the guy who does that show? You're Ed Burns!” David Simon answers them proudly. “Yes, I am,” he says. “Yes, I am.”

Homicide: A Year on the Killing Streets by David Simon
Canongate, £12.99; 656pp Buy the book

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