America had seen the president shot, again and again on the vivid slow-motion videotapes, and the nation had seen John W. Hinckley Jr., gun in hand, wrestled to the ground again and again that day 15 months ago.

So the shock ran deep yesterday, as did the anger and disbelief of many, after Hinckley was found not guilty by reason of insanity of committing the crimes that millions had watched in horror.

On streetcorners and in office buildings, in bars and restaurants, there was strong criticism and even a sense of betrayal toward a criminal justice system that appeared to make it too easy for defendants to successfully plead insanity--especially a defendant whose family had money.

Among 25 persons interviewed near the White House, the Capitol and the U.S. District Courthouse, there was a general belief that the concept of the insanity defense itself remains an important safeguard for the mentally ill, but that the law as written unfairly favors defendants, particularly those able to afford the best lawyers and psychiatrists.

"Money will do anything for you. That's what this trial was all about. He bought himself the big hotshot lawyers," said Melvin Jackson, 28, as he stood eating a bag lunch of fried chicken on the sidewalk outside the Federal Trade Commission on Pennsylvania Avenue, where he was working moving furniture.

For Donna Wertz, a tourist from Cypress, Calif., the verdict was the latest evidence of "a society gone wrong" because the laws appeared to have leaned far too heavily in favor of criminals rather than victims.

"We visited Ford's Theatre yesterday. You know it didn't take them long to catch John Wilkes Booth and take care of him. We as a society have gone wrong since then," said Wertz, a 46-year-old technical editor for TRW Inc. and a mother of three. "We as a nation have made Hinckley famous. We spent millions on his trial and he beat us. In a way, he got what he wanted."

Wertz and her husband, David, who has served on juries, said they believed the law was unfair in placing the burden on prosecutors to prove defendants were sane, instead of forcing defendants to prove they were insane. "I believe in the insanity defense, but not for this case," she said, "I just can't believe it."

"His daddy is a big, rich, white man; how can he be found guilty in this country?" asked Arthur J. Thomas, 48, a tour bus guide who works near the White House. "Hinckley's father brought in those lawyers and psychiatrists with their degrees higher than the Washington Monument . . . . It's like that rich white girl in California, that little Patty Hearst, she got off easy too. If he'd been black, he'd be long gone" to prison.

"People should really reexamine the insanity defense," said Charles Heuer, a Colorado College senior who is working at D.C. Superior Court as a bailiff this summer and hopes to become a lawyer. "If Hinckley realized he was shooting a man who could die, he was not insane. If he thought he was shooting a house or something, then that is really crazy . . . . He wasn't that crazy."

Outside the U.S. District Courthouse where the verdict was rendered hours before, Chris Emmell, 21, stood in a trench, laying pipe for new construction at the federal court complex. "I thought the verdict was fair. He was guilty but he had some real problems," Emmell said. However, he said Hinckley should have received a fixed sentence instead of an indeterminant commitment to St. Elizabeths Hospital, where he may be reevaluated every six months.

"I think they should take that guy up against a wall and shoot him," said Irving Brodsky, 62, of Silver Spring, a tour bus operator. "A friend of mine got killed in a liquor store on 22nd Street a few years ago . . . . The guy who did it got off . . . . This makes you feel like the whole society is going down the tube."

John Feeley, 38, the office manager of a downtown law firm, said he is bothered that Hinckley might win an early release. "It upsets me," he said, "But then again, with the legal system being the way it is, if you believe in the jury system, I guess you just have to go along with it."

Jacqueline West, a 40-year-old housewife from Southeast, waited in D.C. Superior Court where she was about to testify on behalf of a 17-year-old neighbor accused of robbery. She said the youth could not afford a lawyer and she believed he would be convicted and imprisoned, although she believes him innocent.

"If Hinckley was poor, they'd lock him up and find him guilty," she said. "You know what's gonna happen now? A lot of people are going to shoot at the president . . . . "

Across the court hallway, Thurman Garner, 35, a warehouseman from Southeast, waited impatiently outside Small Claims Court, where he has been trying for more than a year to collect $2,000 from a driver who hit him. "Justice is funny," he said. "It looks like now, you can just do anything you want and just play crazy."