Hank Messick, ace American crime scribe, sits in a booth in a cheap Washington cafe. Before him is a cellophane-wrapped ham and cheese. He is talking about "Trigger Mike" Coppola, late fiendish overlord of the Harlem rackets. Listen:

"He was 5-feet-5 and the scariest character I ever met. When I got up with him, he was liging in Miami Beach, next door to the police chief, growing orchids. His wife had squealed and gotten him convicted for tax evasion. She later went to Europe and killed herself. It's all in my book, Syndicate Wife.'"

Hank Messick's mind is like a geodetic survey of American crime - slightly dated. The names of hoods and goons and crooked cops and alleged international vice lords roll off his gongue like strange poetry - Owney "The Killer" Madden, "Sleepout Louie" Levinson,"Fat Hymie" Martin. They are at once his old adversaries and greatest pals, the source not only of his livelihood, but of his dreams. He has a story about all of them.

Hank Messick, who is 55 now and pauchy, has been founding crime and corruption for nearly three decades - ever since he was a cub on the Waynesville (N.C.) Mountaineer and discovered bootleggers operating practically in the shadows of the town school. (A local cop, in on the scam, caught him in the paper's parking lot and knocked his hat off, also, blackened his eye.)

He has worked on half a dozen newspapers, served as consultant to governors and state crime committees, written 16 books that never caught on.He was a key figure in the eventual clean-up of Newport, Ky., once the vilest small town in America. His book, "Lansky," is said to be responsible for getting one-time Carib-bean syndicate kingpin Meyer Lansky deported from Israel.

Twice, in the '60s, he won a Ford Foundation grant to wander the country investigating organized crime. In the '50s, when he was working on the Raleigh Times, he was featured on TV's "The Big Story" for his expose of a local loan shark racket.That began his national reputation.

He almost seems driven, a man on a erusade. The crusade isn't particularly moralistic, though rural North Carolina roots must figure in. What really seems to turn Hank Messick on, like all crack investigative reporters, is the dark, musky scent of conspiracy.And in that, he is on line with a grand American tradition, from Bob Greene of Newsday (head of Investigative Reporters and Editors, Inc.) to Fred Cook of the old New York World Telegram. Cook, they say, in his day could file a hot one in 13 minutes flat.

Some people would say - and have - that Hank Messick's career as a gum-shoe journalist is an exotic cartoon - a cops-and-robbers, gang-that-couldn't-shoot-straight burlesque huffing and puffing its way through narrow escapes and risks that never quite were. There are old stories about hiding out in ashcans, wearing false noses, being chased down thunder roads in the dead of night by villainous men.

"I don't doubt for a moment he had sugar put in his gas tank a time or two," says Elmer Hall, long-time reporter, now an editor, at the Louisville Courier-Journal, where Messick once worked. "And I know his picture has hung on the wall of more than one bookie joint. He wasn't dreaming that up.The trouble is, Hank always took his investigations too seriously. No sense of humor. It was a war. They were the bad guys."

Hall adds: "Maybe Hank was ahead of his time."

Jim Savage, a veteran of the Miami Herald, another Messick way station (where his stories got the sheriffs of both Dade and Broward counties indicted, though not convicted), worked with Messick for several years. He is a staunch Messick defender. He admits, though, Messick made little pretense at objectivity. "He'd meet with grand jurots, try to suggest list of witnesses and questions. I never questioned his motivation or honesty, just his means sometimes." Messick confirms that, "But I don't think I lost my objectivity."

Messick's greatest disguise, says Savage, was a small diamond pinky ring he would wear on his right hand. "I saw him take it out once in Boston and I knew it was serious that day." Savage and Messick, along with Nick Gage of the New York Times, worked briefly for the Boston Traveler in the late '60s. On arrival, Messick started asking questions about a Traveler stockholder allegedly tied to the rackets, and that was that.

"About the disguises . . . " Savage says, a hesitation in his voice, "I think a lot of people now would like to think of Hank Messick as some guy who used to run around in dark glasses and funny hats looking for scoops. Well, that's not what Hank was about at all. In his time, he was the best . . . " His Modus Operandi

He is explaining how he worked. His wire-rims are off now, on the table. The hair that looks like somebody cut it with a power mover has repeatedly had a tan, beefy palm run over top of it. He is speaking in a big, high, country-boy drawl. He doesn't look tough; he looks tired.

"What would invariably happen is they'd send me out on a routine assignment and I'd know why - maybe I ask more questions. Then, too, sometimes I got lucky. Like the time in Louisville the city editor came in and said, 'Messick, there's a sergeant down at county police headquarters. He wants tolk.' I had been at the paper three months. We ended up getting the chief indicted." (The chief resigned the next day; all charges were later dropped.)

Perfect pause. 'You know what happened to the sarge? They got him fired and he went into the electrical business. About a year ago I called him up. He'd become a born-again preacher. I thought that was an awful waste of a damn good cop."

"This business," says Messick, "is all a matter of winning confidences. You see, boys like me, the country hick, are oftern underestimated." Messick is from Happy Valley, N.C. "That's hard by Aho."

The talk drifts to men theoretically on the other side of the [WORD ILLEGIBLE] J. Edgar Hoover, for one, Messick has heard that Hoover once wrote in the margins of a memo: "I will not allow a rate like that Messick any help." Thinking on this makes him chuckle. Hoover, subject of a hard-hitting if obscure Missick biography, was convinced Messick was out to spread sensationalist lies.

Hoover was also convinced, Messick says, there was no such thing as the Mafia. "They had to invent this whole 'Cosa Nostra' notion just to get him to take a look at it. He was on record as saying there was no such thing. He wanted to say away from corruption because he knew it would lead to politicians on a local level."

"You see, things don't change much. It's always an alliance of crime, business and politics."

Messick's own theory of organized crime is that mobs know no ethnic limits. "The Sicilians are just one wing. The most obvious thing about crime in this country is that it's an extension of the free enterprise system. Mobs are just freer in their exterprise." Conspiracy Theories

Talk of Richard Nixon. Messick roiled waters there, too. In the current files of the CIA, in a chunky folder marker "Messick," there is a newspaper clipping, dated Oct. 9, 1969, that begins: "President Nixon slammed the doors on crime writer Hank Messick after an article linking the White House to Mafia interests in the Bahamas." Messick acquired his CIA file recently - after maneuvering for a year to get it. He then wrote a hot letter to headquarters demanding to know why he should have been investigated in the first place.

"That's the kind of tabs they keep on private citizens," he says, dropping his voice, a small, conspiratorial gleam in his eyes.

Messick, in fact, has lots of conspiracy theories - on Howard Hughes, professional sports gambling, the Mafia, Richard Nixon, Atlantic City's new casinos, the assassination of the Kennedys.

As for Atlantic City, set to open next week, he says: "The dice-roll there will mark the final triumph of the old syndicates - those boys who started out as young men in the '30s as bootleggers and worked their way into narcotics. No matter who has opened the doors in Atlantic City, the mob will still be there."

No, he doesn't have names - but he could get them.

On Jimmy Hoffa's disappearance: "I wrote a column in the Miami Beach Sun back in '69 saying word was out there was a contract on Hoffa's life." They decided to "'give him lead rather than bread,'" says Messick.

He likes that; a small smile steals up. Last of a Breed

This might all sound like a paranoid kook talking. He knows that. As Bob Greene of Newsday once put it:

"Everything in this business is degree. If you're around awhile, you can't help looking for 'patterns.' The postu-late is always: 'Am I gonna find a conspiracy?' It's a psychological inevitability. Messick's got it. I've got it."

Messick moved to Florida in the mid-'60s, to Ft. Lauderdale, where he still lives, partly for the sunshine, mostly to get close to Miami's syndicates. He went ot work for the Herald under contract as a special writer. He left when he couldn't get any of his stories in the paper anymore.

"Every 10 years a paper gets an attack of virtue. Then they go back to the status quo." He shrugs, lets it go.

Then, "The American public doesn't want to hear the truth. It wants entertainment. My stories and books always told it like it was."

He seems like an old campaigner in a dry season - a cowboy whose West is moving on before bhe does.

He can't even get in to see an IRS agent today, he says. Once he had special access to the raw files. They'd even assign him a research secretary. He thinks it was Hoover who put the work out to blackball him anymore, though, now that Hoover's gone. Still, its a different ball game.

"The golden age for my kind of work was from '61 to '63, when Bobby Kennedy was attorney general. People don't want to hear about organized crime nowadays. They throw mudballs at it. Unless it's 'The Godfather.'"

A dozen years or so ago, Messick turned to writing books. He's never had a hit. His latest, "The Politics of Prosecution," about the trial of former Illinos Demorcatic governor Otto Kerner (he thinks the trial was a vendetta inspired by Nixon, who had lost Illinios and the presidency in 1960 by the narrowest of margins) is charged woth electric, crimefighter prose. You can almost hear Walter Winchell narrating. Messick's proud of the book. His publisher thinks it's only a regional sell.

Maybe he's the last of a breed, he muses. "I get real sentimental watching 'Lou Grant.' I guess I miss the fellowship of a paperr. Books are a lot lonelier. You know, I was always the fatest writer wherever I worked. In Lousvile, on Derby day, we'd all have to go out to the track and file feature sopy. Hell, i'd be back and finished before some of those ol' boys had even found a story."

Tat sounds a little prideful. He considers. His seamed, country-boy face eases into a smile. "Somebody once told me I've gotten so far in this business because I look exactly like what I am: a shambling hillbilly who just asked a lot of qeustions."