THE DEAF MAN is back to taunt the men of Ed McBain's 87th Precinct, Lawrence Sanders has transgressed to the Fourth Deadly Sin, and tourists watch as the body of a man in a blue suit falls through the paper target on the firing range of Margaret Truman's FBI.

Mystery writers have not recessed and offer suspense and entertainment to replace the Capitol Hill show now that Congress has passed the budget resolution and fled Washington in August.

Anger is The Fourth Deadly Sin (Putnam, $17.95) for Lawrence Sanders, who has confronted the transgressions of pride, greed and lust in earlier books. One has to wonder what Sanders, more than halfway through the seven deadly sins, will do with sloth and gluttony.

The Fourth Deadly Sin marks the welcome return of Edward X. Delaney, retired chief of detectives and creator of those wild, wet, stuffed sandwiches that he eats poised over the sink. It's conceivable that someone might kill for one of Delaney's super sandwiches as the sin of gluttony.

Dr. Simon Ellerbee, a psychiatrist considered a "saint" by patients and colleagues, is found murdered in his consulting office, his skull bashed by a ball peen hammer. The public is fearful and aroused, and Dr. Ellerbee has an influential father-in-law. It's a sticky situation, and New York's first deputy police commissioner turns to his friend, Delaney, who has taken early retirement because he could not stomach departmental politicking.

At stake may be the progress made in the department's program to advance qualified minority officers. The deputy commissioner has pushed the appointment of a Puerto Rican to the post of acting chief of detectives. Michael Ramon Suarez is competent but has not had time to get his act together, and now his head is in the noose.

Delaney, who has adjusted to retirement with a second wife and now has time to build new sandwich concoctions, agrees to take the case "unofficially" if the police department details some of his former aides to help him. They do the painstaking donkey work of checking motives, opportunity and means without progress. Finally, Ellerbee's widow, a regal beauty and herself a successful psychologist, agrees to break the confidentiality of her husband's files and releases the names of six patients with the potential to explode into violence.

It then becomes a search for motive in the dark corners of troubled minds. Among the six patients are a young woman dominated by a fearsome mother, a recluse who dabbles in the occult and is afraid to leave her overheated, cluttered apartment, an ex-boxer and meat merchant with a terrible temper and a battered wife, and a stockbroker who is afraid to come out of the closet. Or might the murderer be someone else than one of the patients, who are obvious suspects?

It is all too easy to patronize Sanders as the author of best-selling blockbusters wrapped in a slick, glossy package for the mass market. He is often guilty of overwriting, sensationalism and pandering to the taste for sex and violence.

All this said, Sanders is a good storyteller. He has a sense of sin and evil that serves him well as a crime novelist. His first novel, The Anderson Tapes, was an innovative thriller- caper using electronic eavesdropping and surveillance. The other earlier books, including the first two deadly sins, were good popular novels with lusty characters and well-paced suspense. Of late, the quality has slipped, and his books have lapsed into vulgarity, clumsy prose and boring detail.

The Fourth Deadly Sin is a return to Sanders' earlier form. It is leaner than the recent books. The suspense never lags. It is the entertainment novel, easy to read and hard to put down, near its best. TFBI as Scene of the Crime

A BODY PITCHES forward to burst through a paper target with a pockmarked heart as 200 tourists watch the marksmanship demonstration on the FBI firing range.

It's a corker of an opener for Margaret Truman's sixth -- and best -- suspense novel featuring capital mayhem in the nation's capital. In Murder at the FBI (Arbor House, $15.95), Truman gives more attention to plot and character than in earlier books and relies less on the trappings of the Washington scene to carry her story. She is, if not inspired to special distinction, a competent professional who can give us some entertaining and suspenseful moments.

The body on the target range turns out to be one of the FBI's own agents. Director Shelton's first reaction is to invoke J. Edgar Hoover's dictim: "Never embarrass the Bureau." A special team codenamed Ranger is organized to investigate the murder -- quickly and quietly. It is made abundantly clear that the murderer should be found outside the agency. A terrorist or two would do just fine.

Assigned to the Ranger team are Ross Lizenby, who had been working on a special project with the murdered agent, and Christine Saksis, a strikingly beautiful half-Passamaquoddy Indian from Maine. They have been carrying on a passionate love affair in defiance of FBI rules.

It is Chris who ignores orders and digs up information that leads to the dead agent's embittered wife and a muckraking author, whom Chris confronts on Fire Island. Was the agent killed because he was preparing to leak secrets for an expos,e of FBI dirty tricks?

Chris finds her romance is souring as Lizenby turns moody and enigmatic. Her only help, as she pursues the case on her own, comes from a former lover, who is an activist for American Indian rights. In the end, Chris finds a shocking truth that shakes both the FBI and her life.

Truman writes a lively Washington scene with the sure hand of one who knows her way around the streets, institutions, restaurants, watering holes, people and politics. Her characters have more substance than those in previous books. If the plot gets overly complicated, things work out quite satisfactorily in the end.

But the prose still lacks style and verve and can turn turgid. Here is Chris, ruminating on the strained relations with her lover and deciding not to confront him:

''Besides, when he was like he was at that moment, any cognitive analysis of the situation was short-circuited by a pure rush of emotion, a tiny internal switch tripping off the conduit to the head and opening a valve to the heart." The Deaf Man Redux

THE DEAF MAN, a seemingly indestructable arch-criminal to rival Dr. Moriarty, returns to the grief of the homicide squad of the 87th Precinct. And not without a little disappointment for devoted fans of Ed McBain's 87th Precinct saga, the longest-running, most popular and most professional of the police procedural series.

Light Black Horses (Arbor House, $15.95) is the latest in the series, which began three dozen cases ago with Cop Hater in 1958. The cops -- Steve Carella, Cotton Hawes, Bert Kling, Meyer Meyer, Andy Parker, Art Brown, Dick Genero -- have become old friends with whom readers have shared good and bad times. This has been a superior series because McBain has not rested on his popularity but experimented with new formats and approaches. By the law of averages, he has to misfire a few times.

In Light Black Horses, he switches the narrative back and forth from the Deaf Man devising his diabolical plot to the befuddled policeman trying to decipher the Deaf Man's cryptic messages. The result is a choppy narrative without focus. And the black comedy is uncharacteristically heavy-handed.

Once again it is only by dumb luck that the 87th Precinct cops foil the Deaf Man, who first appeared in The Heckler (1960), then later in Fuzz and Let's Hear It for the Deaf Man.

The Deaf Man's messages -- photos of eight black horses, six police shields, two nightsticks, three handcuffs, etc. -- arrive addressed to Carella as he is investigating the murder of a young woman bank teller, whose nude body was found in a park. It is only a hunch that leads Carella to link the woman's death with the Deaf Man, whose specialty has been bank robberies.

In the end, all the members of the 87th Precinct homicide squad escape with their lives only because of the clumsiness of Genero, not the brightest of cops, who stumbles on the surprise that the Deaf Man had arranged for a Twelfth Night party at the station house.

"Next time," the Deaf Man is thinking as he walks away in the falling snow. Murders in Duplicate

IN Shadow Kills (Beaufort, $15.95), Jack Hawkins, a wheelchair-bound mystery writer, painfully learns that someone can hate him enough to duplicate the fictional murders in his books, leaving blood- splattered copies by the corpses. Taunting messages follow with the accusation that Hawkins is the one really responsible for the murders.

One has to admit that this is not exactly your most believable plot. But, then, that's the beauty of having a psycho killer -- you don't have to worry too much about credibility if a mad man is on the loose. Who can say it's far-fetched?

W. R. Philbrick's first mystery was Slow Dancer, which introduced a female sleuth last year. In Shadow Kills, his narrator- sleuth is a paraplegic. Hawkins, a former civilian employe of the Boston police department, was hit by a stray bullet in a rowdy brawl at a cop hangout-bar. The bullet shattered his spine, his marriage and his life.

Now he has a new career as a successful mystery writer and a loving girlfriend who accepts his handicap better than Hawkins does himself. We share in Hawkins' frustrations and triumphs as he tries to adjust to a life in a wheelchair -- the struggle of preparing meals or getting in and ot of bed, his specially equipped van, his bouts of depression and self-pity.

Philbrick tends to get heavy-handed at times. He lingers over Hawkins' sex life. His murders are spectacularly grisly and lurid. The confrontation scene lasts too long. But if the result is uneven, the suspense does build as a city and police force panic with a psycho killer striking again and again.