• In Union, South Carolina, a town that last October earned its own pin on the map of American crime, the rage at Susan Smith's actions has gradually given way to more complex emotions. People are still appalled by the way she let her Mazda slide off a boat ramp into the waters of John D. Long Lake with her young sons Michael and Alex strapped into their car seats. They are still outraged at the ease with which she convinced the world that she was the grieving victim of a dark-skinned stranger. But the cries for the death penalty, if not entirely silenced, have quieted. And instead of remaining amazed that a 23-year-old woman, to all outward appearances a loving mother, could harbor such profound unhappiness or anger, the people of Union now marvel that their quiet town could have been the scene of so many tawdry and desperate entanglements.

    Bit by bit over the past few months, local newspapers have chipped away at the veneer of normality on Susan Smith's life and uncovered beneath the National Honors Society membership and "friendliest girl" yearbook title a morass of sexual exploits and personal losses. As the murder trial of Susan Smith begins this week in Union, Judge William L. Howard Jr., who is barring all cameras from the courtroom, has indicated that the proceedings will not come to resemble those under way in O.J. Simpson's double-murder case. But the 10-page, 74-item juror questionnaire indicates that both the defense and prosecution teams will be grappling with explosive emotional material. "There may be some testimony about extramarital affairs," begins one question. "Do you have any personal knowledge of a situation that involved incest?" inquires another.

    Pleading that his client is either guilty but mentally ill or not guilty by reason of insanity, lead defense attorney David Bruck is expected to argue that Smith -- who wrote a detailed confession -- was psychologically destabilized by a lifetime of betrayals: a father who killed himself, a stepfather who molested her, a husband who cheated on her and a boyfriend who toyed with her affections. The prosecution, led by 16th Circuit solicitor Thomas Pope, is expected to portray Smith's murderous act as the culmination of a life of deceit and manipulation. In reality, both characterizations may contain elements of truth.

    Certainly Smith was scarred by the suicide of her father Harry when she was six; in her bureau drawer she kept his coin collection and an audiotape of his voice. But she and her two elder brothers seemed close to their stepfather Beverly C. Russell Jr., the local businessman her mother Linda married in 1979. The divorced father of three, Russell eventually became prominent in both the state Republican Party and the Christian Coalition. Smith's brother Scotty said late last year that Russell was "the force that held the family together."

    In the end he was also instrumental in blowing it apart. Soon after the murders, it came to light that Bev, as he is known, had been accused of molesting Susan when she was in high school. But it was only last season that the full, shocking extent of their sexual contact became known. In 1987, shortly before Susan's 16th birthday, sheriff's records show that Smith told her mother and a high school guidance counselor that her stepfather had fondled her breasts and put her hand on his genitals after she had crawled into his lap to go to sleep one evening. Linda Russell told the authorities that she confronted her husband, and he did not deny the accusations. For a short time, the family visited a therapist, and Bev agreed to move out of the house. But the abuse did not stop. In February 1988, Susan again complained to a guidance counselor, but in the end Linda and Susan decided not to press charges.

    Now it appears that Smith may have offered several different, conflicting versions of these events. The Charlotte Observer has reported that in 1989 she told a psychiatrist that the molestation was in fact a consensual "affair" that had been going on since she was 15-one that she was happy about because she was jealous that her mother was getting all Russell's attention. The Observer also quoted unnamed sources as stating that Russell admitted to authorities that he and Smith continued to have sexual relations until as recently as six months before the murders.

    Not until all Union learned of the abuse, however, did Bev and Linda split up. In February he moved in with an aunt, and in April he abruptly resigned from the state Republican executive committee, stating in part, "I'm at the point where I can hardly function as a committeeman. I wish all this would pass ... My brains are not functioning properly." In April, Russell also released the following statement: "I am responsible for and ashamed of what happened. I appreciate the fact that some of my friends and family have tried to speak up in my defense. But they don't know what I did. I am finally getting the professional help that I need."

    For Smith, it seems, the attention from Russell was just one of several emotional dramas played out during her high school years. She first attempted suicide at 13, then tried again when she was 17, reportedly after a fellow employee at the local Winn-Dixie supermarket, a married man, ended their romance. This second try, an overdose of aspirin, landed her in the hospital, where doctors diagnosed her condition as an "adjustment disorder" -- an inappropriate reaction to stress.

    Susan then took up with another co-worker, David Smith. The second of three children born to Barbara and Charles David Smith, a U.S. Navy veteran who twice served in Vietnam, David had his adolescent troubles as well. His mother is a devout Jehovah's Witness, but David chafed under the sect's strict rules and social isolation. "I wouldn't say David had it easy," says Christy Jennings, his first girlfriend. "I mean, for a long time [David and his siblings] kept to themselves and could only play with some of those kids out there where they were raised up." An invitation to Christy's house marked the first time David had celebrated Christmas. "It just overwhelmed him," Christy recalls. "He was just so happy." Eventually, David moved out of his parents' home to live next door with his great-grandmother.

    Not long after Christy and David's relationship ended amicably, David began dating Susan, attracted by her vivacity and "million-dollar smile," he would later say. They courted about a year before marrying; when they wed, David was 20, Susan 19 and two months pregnant. But the marriage ceremony was bracketed by tragedy. Eleven days before the vows, David's brother Danny died of Crohn's disease; within a few months, his father attempted suicide. David and Susan were a tempestuous couple. No one knew from day to day whether they were together or apart. "Both of them were really immature," says a friend. "Neither of them was exactly what you'd call virtuous."

    Their pattern seemed to be public accusations of adultery, followed by reconciliation. Susan would storm into the Winn-Dixie, yelling at David that she was tired of his messing around. The next week she would come in smiling and laughing. Though her attorneys dispute this, local consensus holds that Susan was the first to be unfaithful. Speaking on the condition of anonymity, several acquaintances say that after Michael was born in October 1991, Susan had an affair. David retaliated with one of his own. The object of his affections was, and remains, Tiffany Moss, a cashier at the Winn-Dixie. David, who has said he believes Susan deserves the death penalty, has put his version of events into a book, Beyond All Reason: My Life with Susan Smith, which will be published next month. If the judge permits, Susan's lawyers will introduce details of his book advance and promotion deals to discredit him as a witness against her.

    David will certainly have much to say about Susan's final affair. According to a deposition taken in March in connection with Susan and David's divorce (which became final in May), soon after she began working at Conso Products in 1993, Susan took up with Tom Findlay, the good-looking, 27-year-old son of the boss. Findlay stated that he and Susan slept together around 10 times, beginning in January 1994. They stopped seeing each other in March or April, he said, because David discovered their affair, but they started up again in September when Susan told Tom she was seeking a divorce.

    Then, in October, Findlay sent Smith the now famous letter in which, it has been reported, he said he wanted to stop seeing her because he did not want the responsibility for her two children. But someone who has seen the two-page document insists that in fact this letter cannot have come as a shock to Smith: Findlay was answering a letter and card she had sent him and continuing a discussion the couple had been having about the reasons they should break up. In his letter, Findlay also writes that he is impressed because she has returned to night school and that he is proud she is taking steps to improve her life. But then Findlay adds that he is upset by Smith's "boy-crazy tendencies." He chides her for kissing and fondling the husband of another Conso employee when they, along with several other people, were nude together in a hot tub at the Findlay estate. "To be a nice girl," he writes, "you must act like a nice girl, and that doesn't include sleeping with married men."

    A week later Susan and Findlay had several conversations in which, according to Findlay, Susan was "upset because David knew, or so she thought, some information that he was going to make public that upset her." At one point when Findlay tried to calm her, according to a source close to the investigation, she lashed out at him with a familiar weapon, claiming that she had slept with a member of his family-meaning his father. Heading back to the office, she told a friend, "I've just lost the best friend I ever had." After work, she picked up her boys from day care, went to meet a friend at the Hickory Nuts bar, then returned to Conso. While the friend watched Michael outside, Susan took Alex inside. This time she told Findlay that she had made up the bit about his father just to see how he would react. Findlay, frustrated, said he would call her and asked her to leave. She did. Three hours later she drowned her children. In her confession, Smith later described her feelings that night: "I had never felt so lonely and sad in my entire life."

    Now a jury must weigh the depths of her despair against the monstrosity of her crime-and the scars of abuse against her own emotional havoc. The weight they give each factor will make the difference between death for Susan Smith and life in prison.