The voice that woke Leslie Walker was urgent.

"Michael needs your help," said the caller. "He's in jail and says he's charged with armed robbery and first-degree murder."

It was 6:25 on a Tuesday morning four weeks ago, and Walker, still groggy, struggled to find meaning in the words. Michael in jail? How could this happen again? "It didn't make sense," she recalls. "It was so wild and implausible."

An editor at the Baltimore Evening Sun, Walker is the author of last year's "Sudden Fury," a true-crime book about the events surrounding the 1984 murder of Bob and Kay Swartz, a repressive Annapolis couple who were stabbed and bludgeoned to death by Larry Swartz, one of their two adoptive teenage sons. The crime, Larry's eventual guilty plea to second-degree murder and his sentence to a 12-year term at the Patuxent Institution had stunned their riverfront community of Cape St. Claire.

And now, if the telephone call made any sense at all, Michael Swartz, the other son -- the one who'd traveled with her on her hardback book tour, the one who had been rejected by his parents and sent to reform school when he was 13 -- had been arrested and charged (with two other men) in another slashing murder.

This was not the way things were supposed to have worked out.

"I had this vision of how Michael and Larry's life was going to be," says Walker. "That with time off for good behavior, Larry would be eligible for release and get out of prison in about two years, and he and Michael would bond again. That Mike was going to make it. And that there would be a happy ending. Now none of that has a prayer of coming to pass."

Walker, a levelheaded hard-news journalist for the past 14 years, hadn't planned to get emotionally involved with the suspects in a grisly parricide when she began covering the case for the Evening Sun. A reporter who had covered murders before, she was trained to be objective. A cool character in person, she initially got caught up in the drama only as a likely subject for a book -- not as a tragedy that would color her life for the next seven years.

But here she was, still tied to the family -- shocked, trying to figure out what to do. Michael's girlfriend, Sue Hilton, had sought her help because he had no one else to turn to. She couldn't turn them down.

This should have been a happy day. Walker was supposed to see the first copy of the paperback version of her book. She was supposed to set off from her Annapolis town house on a book tour; Michael Swartz was supposed to join her. Instead Michael was in the same detention center Larry had been in, facing the same charge -- first-degree murder.

"I was absolutely stunned," she says. "And sad. And angry. Suddenly there's this character in my book rewriting the end of the story."

The Outsider Changes News reporters are supposed to stay objective about their stories and the people they write about. Books, however, demand a point of view. And authors working in certain genres -- biography and true crime in particular -- have sometimes found that the research process completely reorients their original thinking.

In recent true-crime writing, the most scrutinized and controversial example of an author's turnaround is Joe McGinniss's "Fatal Vision," his book about Jeffrey MacDonald, the doctor and former Green Beret who in 1979 was convicted of the murders of his wife and two children. MacDonald maintained his family was slain by four mysterious intruders. And McGinniss had started his research believing MacDonald's version of the story, but came to believe that MacDonald committed the murders himself.

Leslie Walker had none of the access McGinniss did; she was covering the story for a daily newspaper in the hard-news way she was accustomed to: as it developed. By definition she was an outsider.

She didn't want to get too close anyway. The case was distasteful. Bob and Kay Swartz, who'd been killed by the child they originally considered their "model son," had ruled their home as exacting disciplinarians. Neither son, whom the Swartzes had adopted as older children, could meet their new parents' high expectations. Nor could they stand up to the Swartzes' strictures, suspicions and verbal abuse. They had barely survived the neglect of their early childhood. (The Swartzes' young daughter, Annie, has lived with family friends in Annapolis since her parents' deaths.)

There was little in the family's life for Walker to identify with -- and initially she had no trouble keeping her emotional distance. But as she researched her book, she began to sort out her feelings. And as she recognized those feelings -- horror, pity, compassion -- she found herself crossing the line from reporter to author to friend. "It's a different relationship," she says, comparing the role of an author with that of a journalist. "You make it up as you go along, and the rules are not the same rigid rules you maintain in daily journalism. It was impossible not to care about these people. If I'd done that, my book would have had no heart."

Walker, who got to know Michael Swartz only during the course of her research, first saw him at his parents' funeral when she watched both boys shake holy water over their parents' grave. She wasn't able to interview him until six weeks after Larry Swartz's conviction. Initially she didn't trust Michael. He had a reputation around town as a hothead. He had frequent run-ins with school and legal authorities. And on the night of his parents' murder, he had been in a state mental hospital for threatening a social worker with a knife. Even so, it had taken the police a while to rule Michael out as a suspect, and it took Walker a while too. "I was slow to think him innocent," she says.

Most of the time, just staying in touch with him was difficult. Intentionally cut out of his parents' will, without job training or even a high school education, Michael Swartz lived in circumstances that were bleak and variable. "He lived at rock-bottom poverty level the entire time I knew him," says Walker. "He barely had enough money to eat. He often wouldn't have a phone."

Over the years they established a working relationship -- not a close one, but one that touched her. Walker had never known anyone so well whom she felt the system had failed so badly. With the publication of the hardback version of her book, their contact increased. They appeared on a couple of talk shows together, and to get to one of them Swartz took his first plane ride with Walker. So the news that he'd been arrested on a new murder charge blew her away.

"It was hard for me," she says. "I had gone from being leery of him to believing he was completely and totally innocent. And then he goes out and gets himself arrested for murder."

A Decision to Act According to court documents and the police, the case in which Michael Swartz, now 24, was charged with two other men involves the July 9 death by multiple stabbing of Robert Austin Bell, 57, a freelance repairman. One of the defendants lived with Bell briefly this spring after being paroled from a Florida prison where he had served seven years of a 35-year second-degree murder sentence. Michael had phoned investigators about the crime, saying one of the others had committed the stabbing, and he was arrested wearing bloodstained clothes, according to police. He also led police to a bloodstained knife apparently used in the slaying, officials said.

The apparent similarity of the Bell murder to the Swartz slaying -- Bell was stabbed 30 times; Bob Swartz was stabbed 17 times -- startled Walker. "The situation surprised me because I no longer believed he was a murderer," she says. "The thought crossed my mind. But Michael has told the police that he did not do the actual stabbing, and I would like very much to believe that."

But on the morning she first heard about the crime, she could scarcely sort out her thoughts. Follow-up calls revealed that a bail hearing would take place in Annapolis at 2:30. She felt she had to be there.

As an editor, however, she had to drive to Baltimore. Conflicting impulses tugged at her. How would she get out of a 1:30 meeting, she worried. "How was I going to tell these guys I had to disappear?" And who was she to Michael anyway? Her book was finished, so she wasn't appearing as "author." She wasn't covering the story as a reporter. Was she simply a friend -- maybe his only friend other than Hilton, the taxi driver he'd been living with?

At 1:15 she got her pocketbook, left her desk and told her senior editor that she was going down to the bail hearing and wasn't sure he'd see her again that day. At 2:30 she met Hilton inside the district court.

Walker and Hilton agreed to divide up the three 20-minute visits Michael Swartz was allowed that week. Walker used 20 of the 60 minutes. "I was just numb," she says. "And Michael was numb too. It was very, very sad to see him there."

The first thing Walker told Swartz was not to tell anybody what had happened, not even her. She knew that once he told anyone, his conversation became discoverable. She felt she had to warn him.

"The question is, Where do you draw the line?" she says now. "And how do you pull back?"

A Life Altered In the past few weeks people have asked Leslie Walker why she feels compassion for Michael Swartz, and why she doesn't express concern for the recently slain Robert Bell. Her answer is a simple one: "I didn't know him," she says. "I know Michael Swartz and I feel he is the most tragic figure I've ever known."

Walker admits she is surprised at the way the Swartz story has taken over her life. She is 37 now, and has been thinking about the family off and on since she was 31.

Initially, she used up all her accrued vacation to do the research that led to an outline and a first chapter for her book. "You had to act quickly -- before people's memories faded," she explains.

And she took that time off during the height of the Maryland savings and loan crisis when she was the Evening Sun's lead reporter in the Maryland legislature. Then, after she got a contract for the book, she took off an entire year from her job, but still had to finish writing the book on nights and weekends.

Her commitment to the project has cost her a lot. "It has strained personal relationships, and shortchanged them," says Walker, who is single. "I'm a different person now than when I started writing the book."

Her role as the author of "Sudden Fury" (St. Martin's) has also caused her to exempt herself from participating in the Evening Sun's news coverage of the case. "I'm too close financially and personally to be the reporter or editor of record, so from day one I made a personal decision to segregate my role as author-friend from that of newspaper person," says Walker, who as the paper's state news editor does not have responsibility for county stories, but who as the former reporter on the case might normally jump back into it. "My bosses think it's a good move. There is no concern here that there is any conflict of interest."

She is unable to explain fully -- even to herself -- the hold that the tragic story has had on her. Sometimes she points to her acute awareness of the difference between her family life and the Swartzes'. Members of her family -- mother, father, brother and sister -- were always together. Moving a lot because her father was in the Navy, they lived in seven different places before Walker left home to go to college at 17. "We always had each other," she says. "It wasn't frightening to go somewhere new because you always had somebody old with you."

Sometimes she points to the contrast between what she's been privileged to have, and what the Swartz children had. "I'm pleased with my life," she says. "I went to good schools. I have a good job, lots of friends, an enjoyable life -- everything I need. It makes me very sad that other people don't, and the single biggest difference is family -- not money."

And sometimes she points to her own devastation after her mother's death from cancer. "If losing my mother hurts me that much at 35, what did it do to these boys to lose their {foster} mothers again and again when they were little," she says.

These days, four weeks after Michael Swartz's arrest she finds herself on a dizzying emotional roller coaster ride. On the up side, she is absolutely elated because the paperback version of "Sudden Fury" made the New York Times bestseller list its first week out. (The hardback was a modest success.)

She has also discovered that writing the book has enriched her approach to her work. "It has made me less afraid to be compassionate and caring about people I write about. You don't have to be walled off from people."

But she also feels confused, depleted. And she is aware of an acute sadness that Michael Swartz has only one friend to support him and that the brothers are cut off from one another. Just after Michael's arrest, Walker went out to Patuxent to see Larry. She was the first visitor he had had since his brother's arrest. Like Walker, Larry Swartz was surprised at the circumstances of his brother's arrest.

"Larry wanted to talk," she says. "He was still in shock over what had happened to his brother, and felt bad because Michael went through exactly what he had gone through," including the lock-up and detention at Anne Arundel Detention Center. Walker and Larry Swartz talked about his brother's vulnerability, about their shared concern about his ability to handle prison, and how fate just might decide that one day Larry would be free -- and visiting his brother Michael in prison.

And how long is Walker going to visit Michael? She doesn't know the answer, but it's a question that disturbs her greatly -- just as it disturbs her that in all likelihood people wouldn't be writing about her if Michael Swartz hadn't been charged with murder. "I don't enjoy being at the center of negative publicity," she says. "I find myself a semi-character in my own story. I wouldn't have been if Michael hadn't been arrested. And that's not a comforting thought."