"The Rape of Richard Beck," an "ABC Theater" offering at 9 tonight on Channel 7, grew out of a lecture that a Seattle cop gives to police recruits in which he encourages each recruit to empathize with rape victims by imagining himself one of them. But the film didn't just start a lecture, it stayed one, and that's the trouble. What may have been effective in the classroom plays pat and preachy on the screen.

In addition, it seems to prescribe homosexual rape as a kind of sensitivity shock therapy. Richard Beck, 23 years on the force, is callous and cloddish in dealing with female rape victims, and in dealing with his ex-wife, fellow cops and his superiors on the force as well. After the rape, and once he emerges from the aftershocks, he is a model of understanding and compassion. He all but says "Thanks, I needed that" to those who assaulted him.

The character, well played by Richard Crenna, is similar to the one played by the late Vic Morrow in the ill-fated segment of "Twilight Zone: The Movie." Morrow was a bigot who became the victim of bigotry. As with that film, one eventually gets the feeling in "Richard Beck" that the punishment outweighs the crime. On the other hand, though the same points about the nature and consequences of rape have been made in other films, it probably doesn't hurt to have them made again.

Before his baptism by fire, as it were, Sgt. Beck irks the local rape therapist (Meredith Baxter Birney) and a community-conscious lieutenant (Cotter Smith) by letting a known rapist off the hook in order to catch a murderer. In other ways he reveals himself indifferent to the plight of rape victims. Of an elderly lady sitting in the station house, he mutters, "You wanna tell me who'd want to rape her?" When he finds a naked woman in a phone booth after a rape, he cracks, "Wonder where she got the dime to make the call" and later tells pals at a bar that he was "gettin' hot" as he escorted her to a cop car.

Then one night about halfway through the film, "on safari" looking for miscellaneous offenders while off duty, Beck tumbles into the subterranean lair of two malicious loonies who decide they will subject him to the ultimate in humiliation. "You're gonna love it. Hell, it's better than dying, isn't it?" one of them snarls. The camera zooms in on the unfastening of a belt buckle. "You want it, don't you?" one of the rapists asks. The film will be preceded by the usual parental advisory.

Director Karen Arthur shoots the rape scene for the fright that it is, and in general enhances whatever veracity the film has. But the script by James G. Hirsch is as painfully obvious as Sgt. Beck's experience is obviously painful. For instance, after his ordeal, he is subjected to the same sort of medical examination with witnesses present that he himself had witnessed in the first half of the film. And as the trite completion of his ceremonious exoneration, Beck catches the very rapist he had earlier allowed to escape, and just happens to run into him while he is in the process of abducting his next victim.

Not just schematic but veritably symmetrical, "The Rape of Richard Beck" obediently follows TV's Problem Drama formula. Mr. Hyde becomes Dr. Jekyll and the implicit agreement with the audience is that while none of us is expected to believe any of this, the credibility gap is to be overlooked because the filmmakers were thinking the good thought. The film is another consciousness-raising ritual primarily for those who like to congratulate themselves that their consciousnesses have already been raised. Three Sovereigns for Sarah'

"Witches in Salem Village? How unlikely a place for witches," scoffs elderly Rebecca Nurse (Phyllis Thaxter) from her sickbed. Naturally, in only a matter of seconds there is a knock at the door and, yes, Rebecca herself is to be carted off and tried for witchcraft. That is one indicator of the level of subtlety in "Three Sovereigns for Sarah," a three-part public TV drama about the Salem witch trials that begins tonight at 9 on Channel 26 and other PBS stations.

This return to Salem was apparently prompted by a new interpretation of the infamous hysteria of 1692: the idea that neither mass delusion nor mass idiocy were to blame, but that in fact the nation's first real witch hunt was prompted by local political squabbles and disputes over property. The analysis was put forth in "Salem Possessed" by Stephen Nissenbaum and Paul Boyer. Unfortunately, Victor Pisano, who wrote and produced the PBS mini-series, doesn't really give that view much attention until the last 15 minutes of this three-hour work.

Pisano, thinking commercial, prefers to play up the melodramatic aspects of the story and director Philip Leacock, a talented documentary maker out of his league in narrative filmmaking, likes to dwell on such sights as a hanged woman swaying in the wind from the limb of a tree. So single- and simple-minded that it could easily pass for an "Operation Prime Time" syndicated TV movie, "Three Sovereigns" crossbreeds the talkiness of a classroom film with the preoccupations of a Hammer horror movie.

It is inappropriate material for the "American Playhouse" anthology series and for public TV generally. Public television will die trying to be commercial TV. Literally.

Pisano chose the most banal possible structure for his story -- the flashback, just like in all those TV movies on the networks. It is 10 years after the trials and Sarah Cloyce appears before a royal tribunal to clear the names of herself and her two sisters (played by Thaxter and Kim Hunter). They died by the hangman, and she was incarcerated for a year in a chicken coop. "Tell us your story, then, Sarah Cloyce," says Patrick McGoohan as the chief magistrate. Why doesn't he just say, "Begin then thy flashback"?

What raises the stature of this entire ignoble undertaking is the casting of Vanessa Redgrave as Sarah. Although she is seen little in the first episode tonight, she gets to do her valiant-wronged-woman routine to considerable effect in parts two and three (to be seen on succeeding Mondays). When in court she is asked to recite the Lord's Prayer without faltering, a supposed test of witchness, and she stands on a chair to proclaim it proudly, Redgrave certainly exudes authority. It may be that her performance is additionally enhanced by the fact that she is surrounded by a tribe of bad actors acting badly.

A viewer enduring all the Sturm und Drang of this morbid tale might well inquire of the filmmakers, "Why now?" At least Arthur Miller had allegorical ambitions when he used Salem as the setting for his McCarthy-era protest play, "The Crucible." Perhaps one justification for returning to Salem is that the story is a warning against power-hungry and materialistic clergymen, who are once again proliferating in American society. If so, the film really should have delved at greater analytical depth into the mind and motives of the not-very-Reverend Parris (Will Lyman). But he gets scant consideration.

Some of Pisano's dialogue is supposedly taken from actual court records and diaries of the time, so one can overlook the fact that it is unduly arch. But the man is a clumsy dramatist, lazily relying on Redgrave's voice-over narration to supply what he fails to write in to the character interaction. His expository finesse also leaves something to be desired. An early meeting house dispute has characters exclaiming mutual identifications: "Bah, I say, Thomas Putnam!" and "Well, we will vote on it, Israel Porter!"

Because the film includes arduous scenes of children faking possession and throwing Exorcisty fits, "Three Sovereigns" will probably be overly traumatizing for impressionable youngsters. Because the filmmakers were inadequate to the task of making this a fresh and meaningful treatment of a sorry moment in history, "Three Sovereigns" will probably be insufficiently traumatizing for everybody else.