The Most Vexing of All Homicides : Crime: Police agencies have been grappling with how to investigate serial killings, which have sharply increased nationwide since 1977. Two such killers are being sought in San Diego.

In Gainesville, Fla., more than 150 law enforcement officials joined forces to hunt for a killer believed to have murdered five college students in August.

In Seattle, 60 investigators make up the Green River Task Force, charged with solving the killings of 47 women.

In San Diego, the Clairemont-University City serial killings of five women, two as recently as last month, have warranted 27 full-time investigators and seven superior officers--a number criticized by the father of one victim as not being nearly enough.

With serial killings showing a sharp increase in the United States since 1977, police agencies have been grappling with how to investigate what experts call the most vexing of all homicides.

How do police agencies deal with serial killers, and do methods differ from place to place? How many investigators is enough? Are large task forces a successful way to investigate serial killings or just a way to show frightened residents that police really are doing everything they can?

In the Clairemont-University City case, San Diego police have been criticized for doing too little--and too much.

Willard W. (Bill) Schultz, whose daughter Tiffany was the first slain in the Clairemont series, questioned why police in San Diego--the nation’s sixth-largest city--could not devote the same manpower and resources as Gainesville, a college town of 120,000.

San Diego officials say it is precisely because their city is so large that it is difficult to put together a force of 150. This, they say, is hardly a one-crime town. Among other priorities in San Diego County, a 21-member task force is already looking at the slayings of 43 prostitutes and female transients since 1985.

Dick Gerard, a spokesman for the task force investigating the Florida slayings, agrees that the size of a city--and the level of crime within--”makes all the difference in the world.”

Nothing remotely approaching a serial killing had ever happened in what Gerard calls a “once-pristine college town.” Officers from the Gainesville police force, the University of Florida campus police, the local Sheriff’s Department, the state attorney’s office, the Florida Department of Law Enforcement and the FBI have descended on northern Florida to produce more than 5,000 leads--but at the moment, Gerard said, not a single suspect.

“We have other crimes but nothing like this,” he said. “So, we can afford to devote almost all our attention to just one. I can’t imagine what it must be like in a big city.”

Confronted with the criticism of the irate father, Norm Stamper, assistant chief of the San Diego Police Department, did not rule out a multi-agency force to investigate the Clairemont-University City killings, even one as large as Gainesville’s.

“It’s safe to say we’ll accept help from any quarter,” Stamper said. “We have no false pride about the value of seeking or accepting assistance from other agencies. We’re all in this business together. But we’re currently investigating two serial killings.”

Stamper is well aware of the criticisms of “frustrated” family members who, like many in San Diego, wonder why the killer hasn’t been caught. The Clairemont-University City series has produced two arrests. Both men were released shortly afterward.

At the same time, police officials have been criticized for the routine questioning of black men in neighborhoods where the crimes occurred. Those stopped and interrogated include a meter reader for San Diego Gas & Electric and a reporter for KFMB-TV.

The suspect in the Clairemont-University City case is a light-skinned black male, 5-foot-7 to 5-foot-10, with a medium build and short, dark, kinky hair, police say. City Councilman Wes Pratt, who is black, has criticized police for stopping “any and all” males who match the description, and for interviewing most of the black male students at Clairemont High School.

“The possibility of innocent persons being thought of as suspects simply because people are terrified is something we guard against,” Stamper said. “And yet, we have to catch the killer. But on the whole, the publicity generated by the killings has had a remarkable benefit. It has kept leads coming in, whereas in an ordinary case they would have stopped.”

Even now, police hold weekly press briefings on the Clairemont-University City series. No other crime in the city merits such attention. Often, the spokesman handling the briefing apologizes for--as is usually the case--nothing new to report.

But even with a paucity of information, viewers seeing the briefings on television have continued to phone in tips. At last count, there were more than 2,300, so for that reason alone, police say, the briefings will continue.

Stamper calls publicity a “double-edged sword”: It keeps the investigation focused and adrenaline at a fever pitch. But it also fuels political and psychological pressures that make apprehension more difficult and police work highly stressful.

“On the one hand, the fear publicity generates can be an aid to caution and prevention,” Stamper said. “It keeps the community on its toes. But on the other, some people may court suspicions about innocent strangers that aren’t well-grounded and which eventually cause headaches for us.”

Chief Bob Burgreen has called the Clairemont-University City investigation the No. 1 priority of the San Diego Police Department and the manhunt the largest and most aggressive in its history. San Diego police have spent more than $145,000 pursuing the case and have posted a $30,000 reward for information leading to the suspect’s arrest.

But despite “following around six or seven possible suspects,” none are in custody and, Capt. Dick Toneck says, “A piece is still missing. . . . We need a break.” He calls investigators “frustrated.”

Shawn Johnston says they remain that way. A Sacramento psychologist whose expertise is serial killers, Johnston echoes many experts who say such criminals are the hardest to apprehend--no matter how large or exemplary the police force.

Johnston said pervasive media attention keeps a killer “stimulated”--more inclined to murder again but more wary of being caught.

“A serial killer is much different from a mass murderer, such as (James Oliver) Huberty (who killed 21 people in a San Ysidro McDonald’s in 1984),” Johnston said. “With a mass murderer, it’s one incredible explosion. But a serial killer often gives an impression of normality, enough so that they’re incredibly difficult to catch. I remember one (Chicago’s John Gacy) who killed young boys. He was, on the surface, a community leader who sponsored charitable events for children. On the surface, he was a do-gooder in every way.”

Johnston said such killers are usually caught in a “totally random fashion” and not through impeccable or extensive police work.

“It’s most often an accident of some kind, just plain, old-fashioned luck, or a break that just tumbles in the cops’ laps,” he said.

He said that Richard Ramirez, the so-called Night Stalker who terrorized Southern California several years ago, was captured in such an accident.

James Alan Fox, professor of criminal justice at Northeastern University and the author of “Mass Murder: America’s Growing Menace,” is another recognized expert on serial killers. Fox disagrees with Johnston in one important way.

He says the Clairemont-University City killer fits a category of serial murderers labeled disorganized. And thus, he should be “easier to catch,” Fox said, than such organized types as Gacy and Ramirez. The disorganized murderers usually “screw up in some significant way,” he said, “and essentially catch themselves.”

After all, he pointed out, the Clairemont-University City killer was almost captured after being confronted by a maintenance worker at the Buena Vista Gardens apartment where 18-year-old Holly Suzanne Tarr was slain April 3. As it was, he was seen face-to-face by a painter whose description led to a widely distributed composite drawing.

Fox said the Clairemont-University City killer is disorganized and more easily apprehendable for the following reasons:

* In each of five cases, there is no sign of forced entry. He enters through unlocked or open doors in the middle of the day. This is typical of the random method of such a killer.

* In all five killings except that of Tiffany Paige Schultz in mid-January, a knife believed to be the weapon was found at the scene. An organized killer would never do this.

* The murder weapon has been obtained at, rather than brought to, the scene, police say. Apparently, the suspect failed to bring a weapon to any of four apartments in Clairemont, or the single-family home in University City, where the killings occurred.

* Organized killers often hide or bury the bodies away from the crime scene and vary their routine. The Clairemont-University City killer shows no sign of being the least bit organized, Fox said.

* Although police are guarded about details, rape does not appear to be a primary motive.

Fox reiterated that organized killers leave almost nothing at the scene--no hairs, fibers, bloodstains or fingerprints. The disorganized killer “tends to be confused and is a definite loner,” he added. “He’s never the gregarious John Gacy or Ted Bundy type. The disorganized killer kills more impulsively, is less intelligent and often leaves everything behind, including the clues leading to his capture.”

San Diego police asked for and received a psychological profile of the Clairemont-University City killer from the FBI Academy in Quantico, Va. The profile suggested that he is a loner who has a menial job--”if he has a job,” said Capt. Toneck. And he is disorganized in “modus operandi.”

Disorganized killers “generally see someone in their daily routine and get an impulse or may make a mental note and return,” Fox said. “They tend to live near the victims. They don’t get in a car and search out the victims, which is much more the cat-and-mouse game of the organized killer.”

Fox said psychological profiles are “interesting to read, but for the most part don’t help a bit in catching the killer. People on the streets generally don’t wear buttons that say, ‘I’m a loner, suspect me.’ ”

However, police departments usually request them--and usually make them public, he said--because they can’t talk about evidence and such profiles “make them sound like they’re right on top of things.”

Fox said he would not be surprised if the Clairemont-University City killer were apprehended “in the not-too-distant future, perhaps after or during his next attack.”

The San Diego prostitute slayings are, he said, another matter. He alluded to unsolved serial killings in Seattle--the Green River case, involving 47 women, most of whom were prostitutes--and New Bedford, Mass., where nine women known either as prostitutes or drug addicts have been killed, with two missing.

Fox said the “heat” felt by police in pursuing such cases is usually not warranted. Serial killers of prostitutes are, he said, “almost impossible” to catch for these reasons:

* Serial killers of prostitutes are most often organized in methods of operation. As in the San Diego case, they tend to vary their routine and bury the bodies in an area far removed from the crime scene.

* Prostitutes associate with “the worst undesirables” who, if they didn’t commit the crime, are irresponsible or unwilling to aid police.

* People “tend not to get alarmed” if a prostitute is missing for several days--if, that is, anyone knows she’s missing.

* Prostitutes tend not to have adequate medical or dental records, which are almost essential in any identification of a decomposed body.

Fox said the most disturbing truth about serial killers is that their numbers will increase.

Kelley Cibulas, a spokeswoman for the FBI, says 169 suspects identified as serial killers surfaced in the media between 1977 and 1989. No other period in history has shown such a preponderance of this type of homicide, she said.

“The psychological characteristics that make up serial killers--who are generally sociopaths and sexual sadists--are clearly on the rise,” Fox said. “There are a lot more people out there now who have no feelings of guilt or remorse or empathy or concern for others. They care only about their own pleasures in life, their own well-being. . . .

“I’m afraid the rise will continue and that the ‘90s don’t look promising . . . for the public or the police.”