From PEOPLE Magazine Click to enlarge
AT LONG LAST, MICHAEL AND Alex Smith had their day in court. Slowly, their father, David, 25, walked up and down the length of the jury box in the Union, S.C., courtroom last week, letting each juror get a look at snapshots of the two boys. Then he described what his life has been like since last October, when his then-estranged wife, Susan, 23, drowned their sons Michael, 3, and Alex, 14 months, as they sat strapped in the back seat of her Mazda. "I don't know what I'm supposed to do without my kids," David said, choking back tears. "Everything I planned...watching them go to school the first day, watching them grow up—all that's been ripped from me." He broke down sobbing—and there was more emotion to come. As Susan passed David on her way out of the courtroom, she let out a soft cry as painful as it was futile. "I'm sorry, David," she said.

As the jury in Union began the process of deciding whether Susan would be put to death or spend the rest of her life in prison, there was more than enough sorrow, revulsion and mystery to go around. There was also fresh detail about what really happened. In addition to the disclosures in the courtroom, David released a book, Beyond All Reason: My Life with Susan Smith (Kensington Books). Although David has been criticized for exploiting the deaths of his sons, he maintains that his only motive is to ensure that public sympathy remain with the boys rather than Susan. Excerpted in the following pages, the book provides an unsettling look at a marriage plunging headlong toward tragedy.

As David tells it, his relationship with Susan started innocently enough. It was the summer of 1990, and both were working at the Winn-Dixie supermarket in Union. Susan, who he says had been sexually involved with two other store employees, had become the butt of jokes. "I didn't like hearing people laugh behind Susan's back," he writes. "I began to feel sorry for her."

One night they kissed in the stockroom. By the beginning of 1991, Susan was pregnant. In March they were married, and David soon discovered his bride's painful past. Her father, Harry Vaughan, who doted on her, had committed suicide when she was 6. Her stepfather, Beverly Russell, had begun fondling and French-kissing her when she was 15.

As David concedes in the book, both he and Susan were sexually involved with other people during their separations and reconciliations. David dated other supermarket employees. While continuing to sleep with David, Susan started seeing Tom Findlay, the wealthiest and most eligible young man in Union. In the weeks before she killed her sons, she frolicked nude in a hot tub with another man at the Findlay mansion. During the trial, Susan's psychiatrist said she also told him that around the same time she had even performed oral sex on her stepfather Bev.

In the end, of course, Susan's unhappy past cannot explain—let alone excuse—the killing of her two boys. Yet the catalog of Susan's domestic traumas does offer a cautionary tale of how thoroughly a family can self-destruct. David acknowledges as much. "Nothing," he writes with supreme understatement, "can ever approach the horror of what happened to Michael and Alex, but some of the background leading up to it does not show human behavior at its best."

GAIL CAMERON WESCOTT in Union