On April 11, 1835, Richard Lawrence stood trial in the federal court in Washington, accused of firing two shots at President Andrew Jackson as Jackson walked through the Capitol Rotunda. He was the first man charged with the attempted assassination of a president.

Lawrence, a landscape painter about 35 years old, proclaimed to the court that he was the king of England and of Rome and said that Jackson had denied him a fortune and his thrones. A jury returned its verdict in five minutes: not guilty by reason of insanity.

On Tuesday, when John Warnock Hinckley Jr., 26, the son of a wealthy Denver oil executive, stands trial in the federal courthouse in Washington on charges of attempting to assassinate President Reagan, he too will claim that he was insane when he fired on the president.

Apprehended like Lawrence at the scene of the shooting, with gun in hand, Hinckley has formally conceded in court that he fired the shots that wounded Reagan, his press secretary, a U.S. Secret Service agent and a D.C. police officer. The question for the jury at his trial, as it was for Lawrence, will not be whether he committed the crime, but what should be done about it?

Should Hinckley be sent to jail and punished for his offense? Or should he be confined to a mental institution, like Lawrence, because a mental illness impaired his ability to understand that his acts were wrong? Did he intend to kill the president--was that his state of mind? Or did he have a mental illness that would excuse him from any criminal responsibility?

Society's basic concern about crime and punishment when there is an issue of mental illness involved has not diminished since the morning in 1835 when then U.S. Attorney Francis Scott Key, the author of the national anthem, rose to ask whether Richard Lawrence had a "murderous intention" or a "total alienation of mind."

Instead, the insanity defense, much of it developed in the federal appeals court in Washington, has become an increasingly complicated issue, evolving from the simple principle of knowing right from wrong to the complicated notion of appreciating "wrongfulness."

On the eve of Hinckley's trial, U.S. District Court Judge Barrington D. Parker must still resolve the fundamental question of whether the defense should have to prove, by a preponderance of the evidence, that Hinckley was insane at the time of the shooting or whether the prosecution should have to prove, beyond a reasonable doubt, that Hinckley was sane.

The trial itself, which may take about a month to complete, is expected to be the greatest legal drama here since the notorious Watergate trials, which unfolded in the same courthouse on Constitution Avenue.

The shocking factual evidence about the shooting and the pandemonium outside the Washington Hilton Hotel will open the case. Teams of psychiatrists and psychologists, one for the prosecution and the other for the defense, will be pitted in a battle of expertise over the state of John Hinckley's mind that tragic afternoon.

The Hinckley family is expected to testify in what is sure to be a painful portrait of a wholesome, privileged life style that somehow went horribly awry.

The last person found guilty of attempting to assassinate a president was Sara Jane Moore, who pleaded guilty in December 1975 to firing a shot at then-President Gerald Ford.

Lynnette (Squeaky) Fromme, who had carved an "X" in her forehead to demonstrate her devotion to the mass murderer, Charles Manson, was found guilty by a jury in November 1975 of pointing a gun at Ford.

Fromme and Moore were both sentenced to life in prison. Neither woman raised the insanity defense.

Defense doctors who examined Sirhan Bishara Sirhan, who assassinated then presidential candidate Robert F. Kennedy in 1968, testified he was under a hypnotic trance when he shot Kennedy, "knowing next to nothing of what he was doing."

Sirhan, a Palestinian immigrant who said he had come to hate Kennedy for his support of Israel, was found guilty by a jury of first degree murder. He was sentenced to die in the electric chair, but his penalty was commuted to a life sentence in 1972 after the U.S. Supreme Court declared California's death penalty law unconstitutional.

Arthur Herman Bremer, a Milwaukee busboy and admirer of Sirhan's, contended that he was insane in August 1972 when he shot then presidential candidate George C. Wallace at a campaign rally in Laurel. A Prince George's County jury rejected that defense after 95 minutes of deliberation.

Prosecutor Arthur A. Marshall said in that case that Bremer was "obviously a sick man" but not enough to be declared legally insane. The prosecution contended that Bremer's detailed diary, recounting his hunt first for former president Nixon and second for Wallace, showed that his act was "planned, premeditated, deliberate." Bremer was sentenced to 63 years in prison.

Like the jury at the Bremer trial, the 12 persons selected to decide the Hinckley case will face the difficult and subtle task of fathoming the darkest workings of the human mind. When Hinckley pulled the trigger, did he know the difference between right and wrong? Even if he did, did a mental illness keep him from abiding by the law? Must he have been insane to attack the president, knowing that he would be caught redhanded? Was it a suicidal act?

The prosecutors contend that the answers lie in the facts about the crime itself, facts they say will prove Hinckley's criminal intent.

Assistant U.S. Attorneys Roger M. Adelman, Robert R. Chapman and Marc B. Tucker are expected to demonstrate that Hinckley calculated his assault on the president, that he stalked candidates during the 1980 presidential campaign, was arrested in a Nashville airport with three guns just before former president Carter made a campaign appearance, collected books about assassinations, practiced his aim at a Denver pistol range and even considered the kind of ammunition he would use, choosing sophisticated, exploding bullets.

The day of the shooting, in a room at the Park Central Hotel in downtown Washington where Hinckley had stayed, law enforcement officials say they found what appeared to be the motive for the crime. It was contained in an unmailed letter, in Hinckley's own neat handwriting, to actress Jodie Foster:

"Jodie. I would abandon this idea of getting Reagan in a second if I could only win your heart and live out the rest of my life with you, whether it be in total obscurity or whatever. I will admit to you that the reason I am going ahead with this attempt now is because I just cannot wait any longer to impress you.

"There is a definite possibility that I will be killed in my attempt to get Reagan," Hinckley said in the letter. He called his act an "historical deed" with which he hoped to gain Foster's "respect and love."

The government is expected to argue that even with his obsession for the young actress, Hinckley was still capable of seeing that what he planned to do was wrong.

The defense team, Vincent J. Fuller and Gregory B. Craig, both partners in the prestigious Washington law firm of Williams & Connolly, will not dispute the facts about the shooting. Instead, they will focus on what they have insisted all along is the only meaningful question in the case--was John Hinckley of sound mind on March 30, 1981?

Hinckley had been under psychiatric care prior to the assassination attempt and he told an official on the night of his arrest that he had received medication for five months while he was in the care of a Colorado psychiatrist.

Details revealed after his arrest showed an aimless young man, a college dropout unable to meet the academic and social achievements of his older brother and sister. He drifted around Texas, with little more than a television and a guitar, and he favored a diet of hamburgers.

In the fall of 1980, Foster began to receive letters signed "JWH" and "John W. Hinckley" in which the author portrayed his love for her. The actress, then a freshman at Yale University, threw the letters away. She received telephone calls, some of which Hinckley recorded and which may be played at his trial.

That September, Hinckley bought a blue-steel .38-caliber revolver, his first gun, and later the same month bought two cheap .22-caliber pistols--the classic Saturday night specials. In October, he traveled to New Haven and reportedly bragged to a hotel bartender there about his girlfriend--Jodie Foster.

In October he also traveled to Nashville, where he was stopped at the airport just hours before former President Jimmy Carter arrived there for a campaign appearance. Officials confiscated a .38-caliber handgun, two .22-caliber pistols and handcuffs from him as well as a box of 50 hollow point bullets.

He paid a $50 bond and $12.50 in court costs, was released and four days later returned to Texas, where he had tried for seven years to graduate from college.

At Rocky's pawn shop in Dallas, Hinckley purchased two more Saturday night specials. One of them was the gun used in the attempted assassination of President Reagan.

In the long year since the shooting, Hinckley has twice tried to take his own life. The first suicide attempt occurred last May, when he swallowed an overdose of the aspirin substitute, Tylenol. The tablets, which Hinckley had stored away, had been given to him in small doses when he complained of headaches.

The second and far more serious attempt occurred last November, when Hinckley jammed his cell door with a cracker box and then used a jacket to hang himself from window bars. By the time prison officials climbed up to the window from the outside, cut down the noose, broke through the cell door and reached him, he had begun to turn blue.

Hinckley's parents, Jack and Jo Ann Hinckley of Evergreen, Colo., a handsome and well-to-do couple, have sat stoically among the spectators at pretrial proceedings in the case. Each time, the younger Hinckley has greeted them almost self-consciously with a quick wave of a hand from his seat at the defense table.

His parents are expected to testify during the trial, as are his brother, Scott, and his sister, Diane

In a statement released just days after the shooting, Hinckley's parents thanked God for the "miraculous way" he had spared the lives of their son's victims.

Press secretary James S. Brady, who suffered a severe gunshot wound to the brain that has left him with permanent injuries, had six hours of emergency surgery, three more operations, leakages of brain fluid, blod clots, pneumonia and an epilepsy-like seizure before he left the hospital last November.

D.C. police officer Thomas K. Delahanty had a bullet lodge perilously close to his spinal cord. Doctors, reportedly wearing flak jackets, removed it after the FBI learned Hinckley may have used exploding "Devastator" bullets. Delahanty retired from the police force on medical disability.

U.S. Secret Service agent Timothy McCarthy took a bullet in the chest when he lunged into the line of fire to protect Reagan. The bullet passed through his right lung and sliced through his liver. He was back on the job in two months.

The bullet that struck Ronald Reagan lodged an inch from his heart. The surgeon who removed it said "one can only conjecture how much worse things might have been." Reagan's aides say the attempt on the president's life heightened his "sense of mission."

While Hinckley's parents offered their prayers for the injured, they also made a plea for their son:

"We simply ask that you realize John is a sick boy, and that you give him the benefit of the doubt until all the true facts concerning his mental condition are known," they said at the time.

The truth will be for the jury to declare.