On March 30, 1981, America watched horrified as President Reagan was shot by a would-be assassin. Videotape of the scene was available to television within minutes (although it was at first believed the president had not been hit by bullets). Then it was replayed and replayed throughout the day, sometimes in slow motion, sometimes in frame-by-frame progression.

Each time it was shown that day, it was still shocking, still deeply troubling. Each time it is shown now on television, it is troubling for different reasons. The tape has been aired so many times on TV newscasts--sometimes irresponsibly--that the images have all but lost their horror. It has become just another blob of nearly abstract news footage. Something terrible and awful has been reduced through overexposure to a numbingly familiar ritual that passes before the eyes without much effect.

We can hope that political assassinations in this country haven't become so commonplace that they don't leave aftershocks. Reverberations over the shooting of President Reagan and the verdict of the Hinckley jury inspire grim new thoughts about a major preoccupation of the television age: what television is doing to us and our sensibilities, and whether it is somehow making us what we consider to be "less human."

The matter of repeating news footage of the Reagan shooting over and over until it becomes all but a visual cliche'--something that affects us no more profoundly than a commercial jingle does on the 1,000th hearing--seems clearly a result of editorial laziness by TV news producers. These are explicit times, as a visit to any horror movie confirms, and these are jaded, cynical times as well. TV news organizations only make people more jaded, more cynical, and more insensitive to the real horrors of this Earth when they play pictures of them over and over again. The footage of a president of the United States being attacked by an assassin is now used as visual hype, a little kinetic juice to liven up newscast scripts.

Perhaps the worst offender among national news organizations is Ted Turner's amateurish Cable News Network. I once saw the Reagan footage used twice within about three minutes on CNN, the first time in a "promo" for the network, the second time during a recap of the Hinckley trial on a "Two-Minute Week in Review" feature. You'd think that once the Hinckley trial was over, the Reagan shooting could be put back on the shelf for a while--just to give the tape a chance to cool off. But no. Upon the resignation of Alexander M. Haig as secretary of state, CNN used the shooting footage again, during a report on Haig's troubles with the White House.

On a recent local radio talk show, the host said that seeing the shooting of President Kennedy on TV was more shocking than seeing the shooting of President Reagan, partly because this was Our First Assassination in the television age. But we didn't see the shooting of President Kennedy; we heard about it from Walter Cronkite.

Years passed before the Zapruder film of the Kennedy assassination was made public, and because it was film, not tape (and fuzzy, 8-millimeter film at that), it did not have the immediacy of the Reagan footage. We can be grateful, perhaps, that TV didn't have the videotape capabilities in 1963 that it has now, that there is no comparable tape footage of President Kennedy being shot, because if there were, the networks would have played it so many times by now that the nightmare would have been drained right out of it.

Replay technology is still fairly new to television. The first law of television is, if you can do it, do it to death. News producers can call up almost any piece of footage with little more than the snap of their fingers, and because they can, they do, whether or not the footage is necessary to the story being told. They want to keep the picture changing as much as possible because they live in terror a viewer will suffer a split-second of boredom.

In other words, the footage of President Reagan being shot is used by news producers the same way they would use a stock shot of a thunderstorm on a weather report--or, worse, the way a Hollywood producer uses car-chase and car-crash footage on "The Dukes of Hazzard" and "CHiPs." It was rarely necessary in reporting on the Hinckley trial to replay the shooting footage. But there weren't many other "visuals" available with which to illustrate the story; courtroom sketches are static and all look alike. And so the shooting footage was dredged up time and time again.

And a vicious, lunatic act was turned into video filigree. At some point the scene stopped being tragic and started being humiliating; this was a president of the United States being shoved into a limo day in and day out on television, after all. And then, the end result of unchecked overexposure of any set of images: meaninglessness.

Some people say television is turning us into unfeeling zombies. The over-use of the Reagan shooting footage is the kind of offense to decency that makes one think they may be right.

Television, which figures in almost everything that happens in our culture, may figure in this case in other ways. It contributed to the emotional environment in which something like the Hinckley verdict, and the assassination attempt itself, could occur.

Television both reflects and helps determine national moods and attitudes. We don't know which it does more. As infuriating as the jury's verdict may be, it is consistent with the screwy value system represented and endorsed night after night in prime-time television entertainment.

For years, for centuries, a primary theme of literature and theater was the struggle between good and evil. Until the '70s, and Watergate, this was also a dominant theme of television fare. Though they differed substantially in approach, the premise of both "Dragnet" in the '50s and "Hawaii Five-0" in the '70s was that the good shall prevail and the bad shall suffer.

But somewhere along the way, TV began to "understand" the criminal, perhaps too well.

People who think in terms like "wickedness" are considered unsophisticated, naive, even simplistic. But we can accept the higher contrasts in dramatic fantasy. On the simple escapist level, it may serve therapeutic, socially beneficial functions to indulge this fantasy. If the idea that all evildoers pay for their crimes is unrealistic, it's still reassuring to see it acted out in make-believe.

At some point, the public's faith in TV's fantasy law enforcers dissolved--perhaps at the same time its faith in real authority figures, like presidents, tottered. Lt. Kojak, Barnaby Jones, Starsky and Hutch, even Marshall Matt Dillon ("Gunsmoke") are gone now. It is very difficult now to tune in a TV program in prime time and see justice done. In order to see justice done on television, you have to watch old reruns.

Criminals have ceased being evil and are now portrayed as "disturbed." TV movies like "The Jericho Mile" celebrate convict chic, and say society has victimized the men behind bars as much as they victimized society. This stance is passed off as sensitivity in the same way some may view the insanity defense as compassionate.

Attempts to revive law-and-order TV last season were colossal failures--shows like "Today's FBI" and the drooling "Strike Force." What the surviving good guys on TV battle nowadays is not bad guys but that all-purpose foe, The System. (In a cover blurb on the Hinckley verdict, Time magazine asks this week, "Is The System Guilty?") NBC's preachy coroner on "Quincy" is at odds with higher-ups more than he is with criminals. "Hill Street Blues" is about a tribe of cynical cops who are as threatened by city hall bureaucrats as they are by urban terrorists.

Members of the 4077th Mobile Army Surgical Hospital have been fighting the system--not "the enemy"--for 10 years on "M*A*S*H." Heroes and heroines have all but disappeared from TV. Lou Grant had his heroic side, but it was compromised by the off-screen political activism of the show's star, Ed Asner, and now "Grant" is dead.

When popular entertainment abandons the concepts of good and evil, is it also abdicating its role in portraying the difference between right and wrong? People tuning in prime-time TV in the '80s do not see right conquering wrong. To the contrary, they see villains treated as heroes on programs like "Dallas," "Dynasty" and "Flamingo Road." If these programs are a response to moral confusion rather than a contributor to it, their proliferation nevertheless helps perpetuate the idea that right and wrong are outmoded commodities, that the wages of sin amount mainly to money, power and glamor.

Concurrent with the demise of the hero has been the rise of the celebrity crook. The great god of fame is continually worshiped in fact and fiction on television, and people like Charles Manson, Sirhan Sirhan and G. Gordon Liddy are accorded celebrity status in glamoroso interview surroundings. At least one TV reporter referred on the air to Hinckley's trial as his hour in the "limelight," and the mad act of an assassin is reduced to the level of publicity stunt.

The lines between hero and anti-hero, and between fame and notoriety, are shriveling away on TV. It's no wonder audiences hunger for, and respond to, clear-cut depictions of heroes and villains in movies like "Star Wars" and "Raiders of the Lost Ark."

We can't expect television to be preacher, teacher and policeman to the nation; it is not there to keep people in line. Those who would use it to that end are the ones from whom we have the most to fear. But there is something unsettling about the way television has abdicated the old values. It's as if, somewhere along the way, the Judeo-Christian Ethic became "controversial." Or at least unfashionable.

Television is dominant in this society. It's the bulletin board everybody reads. If the Hinckley verdict gives rise to the feeling that something is terribly wrong somewhere, television is not a bad place to start looking.