The first question when Kelly Nolan didn 't come home June 23 was simple:

What happened to her?

The answer two weeks later was heartbreaking, but remains incomplete.

Nolan 's body was found July 9 in a wooded area in the town of Dunn, 10 miles south of Downtown Madison. Ten months later, police still don 't know who put her there, while a cause of death and a motive for the crime have never been released by authorities.

Since the death of Nolan, a 22-year-old UW-Whitewater student who disappeared after partying on State Street, Madison residents have seen two more tragic killings of young people in which the questions far outnumber the answers.

Police have not identified any suspects or motives in those crimes, either -- the Jan. 28 fatal daytime stabbing of 31-year-old Joel Marino in his home and the killing of Brittany Zimmermann, a 21-year-old UW-Madison student on April 2 -- raising possible concerns about whether police are holding back too much information about the cases and about their own progress in solving them.

"When killers are on the loose, law enforcement has a responsibility to maximize the information that it gives to the public, " said Jack Levin, a professor of criminology at Northeastern University in Boston and author of books on homicide who has consulted for police, prosecutors and defense attorneys in murder trials.

"Otherwise the public cannot take precautions, " Levin added. "And if police investigators would simply take a look at cases of murder that have been solved thanks to the involvement of members of the public, they might think twice before they conceal evidence. "

Madison Police Chief Noble Wray said detectives are holding back only what they must to make sure the cases can be solved, with some key details known only to investigators to help them weed out false confessors and trip up the guilty. He also said investigators were working very hard on the cases -- which are more difficult to solve because they are all believed to be random attacks by strangers with no ties to the victims -- and he stressed that more was going on behind the scenes than people realized.

Police also are working now to close three other open homicides -- of Larry Gardner, George Thomas and Kevin Cobbins -- that are not considered to be random killings.

Wray said he recognized that the random nature of the Nolan, Marino and Zimmermann slayings creates more demand from the public for information, but he noted that police sometimes face practical difficulties in providing it.

"For these types of cases you really should get as much out as possible, " he said. "The reason you want to get information out is that random killings create such a level of fear and concern. But the counterintuitive part with this whole thing is that you have such a broad range of possible suspects in these (random killings), that 's it difficult to provide good information. "

Nevertheless, Joel Marino 's father, Lou, may have spoken for many concerned residents when he recently described his frustration with not getting answers from the police like this:

" It takes time, ' they said. It takes time, ' " Lou Marino said. "But we 're all tired of them hiding behind statements that, This is evidence so we can 't tell you about it. ' "

'Losing public trust'

Bill Lueders, president of the Wisconsin Freedom of Information Council and news editor of the weekly alternative newspaper Isthmus, said the police department is losing public trust over what he called "the high level of inexplicable secrecy " in police handling of the cases, especially issues involving the botched handling of a 911 call from Zimmermann on the day she died.

While a Dane County dispatcher made that mistake -- by failing to call back the number when the call disconnected -- and the 911 Center itself then made things worse by providing false information that sent police on a bad lead for two weeks, Lueders said police have over-reacted by refusing to tell the public even how long the call was and other details.

He also noted police had to be prodded for weeks by the media before they agreed to reveal, for better public safety, that forced entry was made to Zimmermann 's building.

"I think there 's been a crisis of confidence that 's been created in the community, " he said. "I think the police department is more tight-fisted with information now than at any time I can recall, and I have been here for more than 20 years. "

Lueders acknowledged that police must refuse to make public some information during investigations. But he said the police increasingly were getting the balance wrong, seeming to opt for blanket denials of requests for information rather than strategic refusals.

"There needs to be tension between what the public is allowed to know and what the police are allowed to keep close to the vest, " Lueders said. "No one disputes that. It 's just that the possibility exists that some of this secrecy is not to protect the investigation. It could be to protect the investigators. "

Wray said police use a three-pronged test to weigh whether information in a case should be publicly disclosed. He said investigators consider how releasing it could affect the case, for good or bad; what members of the public need to know to keep themselves safe; and what the public must be told because there is a legal right to know, such as when arrests are made.

As an example of what he said was his own inclination toward transparency, Wray cited the press conference he called shortly after 911 Center officials held their own conference to partially acknowledge the Zimmermann 911-call mistakes. Wray said the police department had to clarify what he saw as misrepresentations about the incident by center officials because the issue of "public trust " was involved.

Similarly, Dane County District Attorney Brian Blanchard said he understood that the public may want to know more about issues involving the three killings, acknowledging in particular "very intense public interest in (ensuring) the integrity of the 911 system " and in getting straight answers from public officials about the problems.

But he said those concerns could be dealt with over time, while what mattered most now was not publicly disclosing key details that could help investigators find the killers.

"That does give the police an additional tool in trying to get to the truth, " he said.

Solving cases stressed

Other experts also believe strongly that police should err on the side of withholding most information during homicide investigations.

"It 's more important to solve the cases than to inform the public, " said Ruth Kocisko, a college-level criminal justice instructor in Sioux City, Iowa, who practiced criminal law as a defense attorney for 22 years.

"If revealing the details of a case may make it more difficult to solve, then those details need to be very tightly held. "

Kocisko said residents could still be urged to practice common-sense good safety, such as locking doors, without revealing details that could compromise cases or bring additional pain to victims ' families, such as whether a killing included a sexual assault.

Kocisko also said it could be unwise for investigators to publicize their theories of how crimes were committed, because new information could always come in to prove them wrong. She cited the example of the serial sniper killings that terrorized residents of Washington, D.C., in 2002.

"Investigators could have said they were looking for a white man, because most serial killers are white men, " she said. "But it turned out to be a black man and 17-year-old boy. "

While also urging caution with details when it 's absolutely necessary, Levin used the same case to argue that police too often "underestimate the value " of informing the public.

"In (that) case, the two killers were brought to justice thanks to an anonymous tip from someone who saw their car in a rest area near the side of the highway, " he said. "If it weren 't for the public, there may have been several more murders before they were caught. There were already 10 as it was. "

Tips totaled

Madison police say they do welcome tips from the public and have received many that have been worked diligently in the three slayings. By mid-April, the department 's Crime Stoppers line had received 200 tips in the Zimmermann case, for example, and 95 in the Marino investigation, police spokesman Joel DeSpain said.

Detective John Sommers, co-lead investigator on the Nolan case, said police also work hard to get the balance right between the public disclosure and non-disclosure of information. But it 's a serious juggling act police must do, he said.

"Our ultimate goal is to assure public safety while seeking to achieve justice for a victim and their family in tragic instances such as these, " Sommers said in a recent e-mail to the State Journal. "The (job) for police is to balance public safety and need to know (with) case integrity and protection of the victims ' families from external invasion of privacy. "

Sommers added, "When there is information to release, we 'll do so as promptly as possible. Otherwise we 'll continue to move the case forward. "

And Madison police maintain that a fair amount of information that can be released has been in the three cases. That 's most true in the Marino investigation, where police have developed a sketch and a DNA profile of the suspect and some details about the circumstances of the crime are known through police comments, search warrant results and interviews with Marino 's friends and family members.

Less is publicly known about the Zimmermann homicide, while virtually nothing new has been revealed about the Nolan case since her body was discovered.

In the first public accounting of progress to date in all three investigations, police told the State Journal last week that more than 800 people have been contacted in the Marino investigation, with 80 possible suspects developed and cleared for now and more than 2,000 pages of reports generated; for Nolan, 588 individuals contacted and 192 tips followed up, resulting in 1,200 pages of reports; and for Zimmermann, so far, there have been "hundreds of individuals contacted " -- police could not be more specific late last week -- and 36 possible suspects contacted and ruled out for now, producing 1,420 pages of investigative reports.

Neighborhood view

In the Bassett neighborhood, where Zimmermann was found slain about 1 p.m. in her apartment on West Doty Street -- authorities will not say how, but a source close to the investigation told the State Journal she was stabbed -- Neighborhood Association Chairman Peter Ostlind said his group was satisfied overall with police communication.

"People certainly would like to see the cases be solved, but I think they understand the rationale that the police department has for releasing what they do release and not releasing what they don 't, " Ostlind said. "Yes, you want to know more, but you also understand the police desire to be able to conduct a complete and thorough investigation. "

Lueders readily agreed that police had a tough job, but he said that didn 't mean the public had to be satisfied with their performance.

"It 's not an incongruous position to be respectful and honor the job that police officers do and expect them to be more forthcoming with information, " he said.

Questions

Beyond the question of who the killers are, many details about the slayings of Kelly Nolan, Joel Marino and Brittany Zimmermann remain unclear. Authorities to this point will not — or cannot — answer the following queries:

About Nolan, who was found dead on July 9:

1. How and when did she die?

2. Was there evidence of sexual assault?

3. Are the police and coroner unwilling or unable to answer those questions? Is the information being held back for some reason, such as to protect the investigation? Or do investigators not know what happened to her, because the body was acknowledged to be in a degraded state after two weeks outdoors in the summer? Officials will not clarify.

4. What do police believe was the motive for the crime?

5. What did Nolan say in an early-morning phone call to her sister April the day she disappeared?

6. How many people have been ruled out as suspects?

7. Who was the second man seen walking Nolan toward her home after bar time and what happened after that?

8. Were any search warrants obtained in the course of the investigation? If so, have the results been sealed and when will they be unsealed? (So far, no search warrant results involving the Nolan case have shown up in the court record).

9. Police Chief Noble Wray said more than a month ago that he would have an update on the Nolan case in a week or two. Where is it?

About Marino, who died Jan. 28 from "multiple penetrating wounds from a sharp instrument":

1. What was the motive for the crime?

2. Was anything stolen from his house?

3. Were there signs of a struggle?

4. Have there been additional search warrants filed since the search of his home on the day he died?

5. Has the DNA profile of Marino's suspected killer been matched to any DNA discovered at Zimmermann's house? Has it matched any other crime or offender on record? Has the process of trying to match the DNA profile begun?

About Zimmermann, who died April 2:

1. How and what time did she die? (Coroner John Stanley has said only that she died from "a complexity of traumatic injuries.")

2. What was the motive for the crime?

3. Was there evidence of sexual assault?

4. Have any search warrants been obtained in the course of the investigation? If so, have the results been sealed and when will they be unsealed? (So far, no search warrant results involving the Zimmermann case have shown up in the court record).

5. What was heard on the 911 call made from Zimmermann's cell phone around the time she was killed that leads police to believe officers should have been dispatched to her house?

6. What time was that 911 call made and how long was it?

7. Was she dead when her fiance Jordan Gonnering came home to the flat they shared and found her on April 2?

8. What is the status of any forensic evidence collected in the Zimmermann case? Has the ongoing analysis produced anything of value?