John W. Hinckley Jr., calm but intent, yesterday watched a graphic, slow-motion videotape of his assault on President Reagan and three other men more than a year ago, then listened to a Secret Service agent's dramatic account of his arrest.

Hinckley showed little reaction as prosecutors laid out for a second day detailed evidence about his attack on Reagan and about his actions before the shooting.

Among the items introduced yesterday was a note beginning, "This plane has been hijacked!" that was found in a Band-Aid box among the belongings Hinckley left in a Washington hotel room on the day of the shooting.

Prosecutors also introduced an assortment of books--from "Romeo and Juliet" to "An Assassin's Diary" by Arthur Bremmer, the convicted assailant of Georgia Gov. George C. Wallace--and news articles about the death of Elvis Presley and the murder of John Lennon.

The evidence included a large assortment of Hinckley's writings, including more than three dozen poems on a variety of themes from suicide to lost love and the "American Dream," which Hinckley wrote is "fast becoming a joke."

At one point yesterday, a witness read aloud a note on the back of a picture postcard of President Reagan and his wife Nancy, addressed from Hinckley to the young actress Jodie Foster. "One day you and I will occupy the White House and the peasants will drool with envy," Hinckley said in the note. After the witness read it to the jury, Hinckley put his head down in his hands, smiled and shook his head.

He glanced swiftly up at the jury after the videotape ended, but looked stonily away a few mintues later as a Secret Service agent recounted the "momentary feeling of panic" that swept over him when he realized that the "pop" he thought was a firecracker was the sound of a gun going off.

"I could hear the weapon going off and I couldn't see it and I felt the feeling of panic, like I had to stop, and I knew something was going on but I couldn't see the gun," Dennis V. McCarthy told the jury at Hinckley's trial in U.S. District Court.

"Then, all of a sudden, the gun started coming out of the crowd . . . . I saw the weapon and I started to dive, just dove toward the weapon," McCarthy said.

The crowd, repelled by the sound of gunfire, began to back off, McCarthy testified, and he saw a man, crouched in a combat position, move forward with both hands clasped around a gun.

That man was John Hinckley, McCarthy told the jury.

McCarthy said he heard more shots as he lunged at the assailant. "I was going through the air. I can still remember the gun going off and a desperate feeling of 'I've got to get to it, I've got to get to it and stop it,' " McCarthy testified.

McCarthy said he landed, coattails flying, on top of Hinckley just as Hinckley had fired his sixth and last shot--the one that richocheted off the presidential limousine and struck Reagan in the chest.

"He was still clicking the weapon," McCarthy testified.

Hinckley's arms thrust forward with his hands gripping a revolver are clearly visible in the slow-motion videotape of the shooting made by NBC cameraman Sheldon Fielman .

As the shots are fired, the videotape shows White House Press Secretary James Brady falling, struck in the head by the first bullet. The film also shows retired D.C. police officer Thomas K. Delahanty as he is struck in the back by Hinckley's second shot. In the film, Secret Service Agent Timothy McCarthy, who was wounded in the chest, has his arms outstretched near a door to Reagan's limousine.

Agents Dennis McCarthy and Timothy McCarthy are not related.

The film, which was edited by the court to remove the most graphic scenes of bloodshed, ends with the pandemonium at the VIP entrance to the Washington Hilton Hotel as Reagan was rushed away and Hinckley was shoved into a police cruiser.

"Did Hinckley put up any resistance in the course of the arrest?" defense lawyer Gregory B. Craig asked Dennis McCarthy.

"None whatsoever," McCarthy responded.

Hinckley contends that he was legally insane at the time he fired on Reagan and could not abide by the law or understand the wrongfulness of his acts.

The prosecution contends that the shooting was a deliberate, planned attack, but the defense has portrayed Hinckley as a lonely, withdrawn young man, isolated from reality and living in a desperate fanatasy world.

For the last two days, the prosecution has presented evidence from 16 witnesses and introduced more than 100 pieces of evidence and two videotapes in its effort to prove that Hinckley planned his crime, stalking both President Carter and Reagan before the assault on Reagan.

The government is expected to rest its case this morning. The defense will then begin the presentation of testimony from Hinckley's family, medical doctors and psychiatric experts to try to show that Hinckley was mentally ill when he shot at Reagan and should not be held criminally responsible for his acts.

When the defense case is complete, the prosecution will present its expert psychiatric testimony to rebut Hinckley's insanity claim.

During yesterday's court session, the jury of seven women and five men also heard testimony from the doctors who treated Reagan, Delahanty and Timothy McCarthy after the shooting, each of whom briefly described the gunshot wounds the three men suffered. Brady's neurosurgeon testified Tuesday.

Much of the testimony yesterday involved the weapons and ammunition that Hinckley used, including sophisticated Devastator bullets that explode on impact. There was also substantial testimony surrounding the introduction of the collection of Hinckley's belongings from a hotel room in Washington and from Hinckley's family home in suburban Denver.

Among Hinckley's writings was a poem entitled "A Reluctant Swan Song" dated Feb. 14, 1981, which begins, "Criticize you may this act of mine . . . . " In the defense's opening statement Tuesday, the jury was told that on that date Hinckley, with a gun in his pocket, went to the apartment house in New York where John Lennon had been killed and considered suicide.

Hinckley's defense lawyers told the jury that Hinckley was obsessed with Jodie Foster but frustrated in his attempts to reach her. In his poetry, Hinckley makes frequent reference to "Jodie," as he did in a writing titled "Amen:" Jodie isn't plastic nor does she cry at the sight of me writhing in pain down in the gutter of Anystreet USA because Jodie will always be Jodie. Don't cry for me Arizona the truth is I brought it on myself in a calculated ways and means by which I would positively hurt everyone around me . . . .