Did the two people apprehended yesterday in connection with the sniper shootings want to get caught? Was there a voice inside them crying out, "Stop me"?

Reports yesterday that the pivotal tip directing police to a liquor-store murder in Montgomery, Ala., had come from someone claiming to be the sniper can't help but raise such a question. So does the fact that the two suspects were found sleeping in a car at a rest stop just hours after police issued an all-points bulletin on the vehicle.

The question has been pondered in many serial-killer cases. Experts who study the minds of such criminals have reached a consensus:

"There is absolutely nothing to it at all," says Alexandria psychologist Stanton E. Samenow, author of the seminal 1984 book "Inside the Criminal Mind" and co-author of the three-volume 1994 text "The Criminal Personality."

"I have been researching criminal behavior for 30 years and I have not found one offender of any stripe who wanted to get caught."

New York forensic psychologist N.G. Berrill agrees: "To think that, gee, maybe at the core they know they are bad and evil and so they want to be punished -- that's criminal folklore."

Yet such folklore is common enough that the phrase "Stop me before I kill again" has gained punch-line currency.

"You hear it all the time that this guy must be screaming out, 'Catch me, catch me, catch me.' But if you look at the behavior, he has done everything possible to outfox the police," says Samenow.

What leads people to consider the notion, he says, relates more to the serial criminal's Achilles' heel -- a sense of impunity. Every time he gets away with another crime, his sense of invincibility mounts. "So he takes more chances," Samenow says, "he becomes less vigilant, maybe about the little things."

In the case of a serial holdup man in the Washington area several years ago, that little thing was a piece of paper that fell out of his pocket at the scene of one crime. "It was a cleaning slip with his name on it," Samenow recalls. "The criminal does something dumb like that and it seems so stupid to most of us that we think 'My God, he must have wanted to get caught.' "

Samenow also credits the tendency to fit the "please stop me" theory to the behavior of serial killers to a 1915 article Sigmund Freud wrote in which he discussed "an unconscious sense of guilt" for which people want to be punished.

J. Reid Meloy, a California forensic psychologist whose book "The Mark of Cain" examines psychopathic killers, traces the popular origin of the notion back more than 50 years to a serial killer named William George Heirens. A 17-year-old University of Chicago student, Heirens committed brutal murders that perplexed the police and frazzled public nerves in the summer of 1946.

It was during his second murder that he left his mark on the bloody history of serial killing. After stabbing his victim in the neck with a butcher knife and shooting her in the head, Heirens scrawled in lipstick on her living room wall: "For heavens sake, catch me before I kill more. I cannot control myself."

But Meloy says that the idea Heirens wanted to be caught isn't supported by research on serial murderers. And even if he did, it still required detective work and luck to find him. Far more likely than serial killers succumbing to guilt pangs, Meloy says, is the public experiencing what's called "wishful projection."

Thinking the killer unconsciously wants to be caught "is simply projecting the desire people have that he be caught," he says. "It is purely psychological."

"A lot of people who do these terrible and horrendous crimes are sociopaths and psychopaths," Berrill says. "They don't want to be caught and they don't have a conscience.

Berrill says there are thousands and thousands of crimes that go unsolved in the United States every year -- Chandra Levy, Jon-Benet Ramsey. "Do you think the Unabomber wanted to be caught? We are superimposing our sense of what it means to have a conscience on these people."

The belief that serial criminals want to be caught is common just before or soon after the criminal is caught. Jeffrey Smalldon, a forensic psychologist in Columbus, Ohio, says that's when the serial criminal is more likely to take bigger risks.

"That behavior is really an expression of the serial killer's need to ratchet up the level of intensity to get the same high he used to derive through the killings at first," says Smalldon.

Smalldon recalls Edmund Kemper, a California serial killer who in the 1970s picked up female hitchhikers near colleges and murdered them.

By the time he had killed four or five women and had frustrated police efforts to stop him, Kemper began hanging out at a local bar fraternizing with off-duty cops, discussing the merits of different guns. He made a point of driving through campus checkpoints with corpses in the trunk of his car.

"It's not unusual at all for serial killers to insert themselves into the investigation," Smalldon says. The public "looks at this kind of behavior and wonders why would they do that if their goal was to remain out of sight? Why would you place a phone call? Why would you write a letter to the police?"

But Kemper was one of the few serial killers experts can recall who turned himself in. After killing eight women, including his mother, he apparently grew weary of being on the run. He called the police and confessed.

But Samenow won't take a killer's word on the subject. "After the fact, sometimes in order to satisfy the authorities, they may say, 'I was getting tired, I wanted it stopped, I wanted somebody to catch me.' But they don't really believe it," he says.

He even doubts the veracity of the lipstick-scrawled plea of William Heirens. "They are not trustworthy," Samenow says. "They'll tell anybody anything in order to manage impressions."

William George Heirens's message to Chicago police after one of his murders, says one researcher, generated the popular but misguided belief that serial killers want to be caught.Those who believe serial killers want to be caught cite Ed Kemper, below right, who turned himself in after eight murders, and William Heirens, top right (in 1946) and above (in 1970), who scrawled an infamous plea to police.