Americans are fascinated by the case of the New York "subway vigilante," and evenly divided over whether the suspect, Bernhard Hugo Goetz, did the right thing by allegedly taking the law into his own hands and shooting four youths who had asked him for money.

According to a new Washington Post-ABC News public opinion poll, among people who say they know enough about the event to have an opinion, 45 percent approve of the shooting and 46 percent disapprove. Nine percent have not come to any conclusion.

More men than women defend Goetz. In homes where there are guns, a majority approves; in homes where there are no guns, a majority disapproves. Rural people, generally more at home with weapons, approve of the shooting more than big-city residents.

But in some other ways the division goes sharply against the grain: People who call themselves liberals, for example, are at least as likely as conservatives to side with Goetz.

The poll also suggests that more than 70 million Americans have guns and that 45 million to 50 million are ready to use them in the most commonly anticipated threatening situation: against an intruder in their house or apartment.

Seventeen percent -- the equivalent of 25 million to 30 million people -- say they have considered buying a firearm for protection and 11 percent -- the equivalent of 15 million to 20 million adult Americans -- say the chances are high that they will.

In the poll, conducted Jan. 11-16, 86 percent of the people interviewed said they had read or heard accounts of the Dec. 22 incident in which the gunman, accosted by four 18- and 19-year-old youths, drew a pistol, shot all four, and left the subway by walking along the underground track to the next station.

That is an extremely high level of public awareness, equal to or surpassing that of almost all national events. It is slightly higher, for example, than the percentage who knew that more than 50 Americans had been taken hostage in Tehran in November 1979. People in the East especially have been paying attention to the subway incident, with 95 percent in the region saying they had heard or read of the case.

Goetz remained a fugitive for several days after the shooting, turning himself in to police in New Hampshire on New Year's Eve. He has been charged with four counts of attempted murder and illegal gun possession. One of his lawyers said Goetz will plead innocent, but the attorney would not say whether Goetz will claim to have acted in self-defense.

News reports yesterday quoted Goetz as telling New Hampshire police that he regretted not having done more. "I would have kept shooting had I not run out of bullets," Goetz reportedly said. "I should have gouged his eyes out with my car keys."

Since the confession, however, the 37-year-old electronics expert has appeared less vengeful. At a Senate hearing in Washington on Thursday, his attorney, Joseph Kelner, portrayed Goetz as someone injured in a previous mugging, afraid of being maimed, who hoped the incident would result in federal funding for job-training programs for minority youths.

In conducting the Post-ABC News poll, interviewers first ascertained whether people were familiar with the subway incident and then asked this question:

"From what you know of the case so far, would you say you tend to approve or disapprove of the man's having shot the four people?"

In all, 1,505 people were interviewed. Among those who said they had read or heard of the shooting, here is how some groups in the population divide:

* People in homes where there are pistols, rifles or shotguns: 54 percent approve, 37 percent disapprove. People in homes where there are pistols but no rifles or shotguns: 62 percent approve, 32 percent disapprove.

* People in homes where there are no guns: 38 percent approve, 54 percent disapprove.

* Veterans of the armed forces: 53 percent approve, 34 percent disapprove.

* People who consider themselves liberals: 48 percent approve, 40 percent disapprove. People who say they are conservatives: 47 percent approve, 44 percent disapprove. People who say they are moderates: 41 percent approve, 49 percent disapprove.

* Men: 51 percent approve, 40 percent disapprove.

* Women: 39 percent approve, 52 percent disapprove.

The survey was conducted by telephone. For figures based on the number of people who said they had heard or read about the incident, there is a theoretical margin of sampling error of about 3 percentage points. That does not take into account other, nonsampling errors that may occur in opinion polling.Polling assistant Kenneth E. John contributed to this report.