Leigh thought her date was going quite well, right up until the point, she says, when she was drugged and raped. It was her first time meeting Jeffrey Marsalis, a gregarious trauma surgeon who had contacted her through the online dating site Match.com. Tall, blue-eyed and engaging, Marsalis had taken her out in downtown Philadelphia, entertaining her with stories of life in the ER. "He seemed a little full of himself," Leigh recalls; still, she was having a good time. She slowly drank one beer, then a second. Their date was in its fourth hour when Marsalis ordered a carafe of white wine, and Leigh excused herself.

"I would never think to be so cynical that I'd stand there and watch as he poured my drink," remembers Leigh, a striking blonde (who, like all accusers in this article, is identified by her middle name). When the 28-year-old accountant returned to her barstool, her glass of wine was waiting. Leigh took a sip.

As she would later testify, the next thing Leigh remembers she was in a dark room, facedown on a bed—and Marsalis was anally raping her. The pain felt as if he were ripping her in two. Her limbs were leaden, her mind sluggish. "Stop, please stop," Leigh mumbled. Marsalis simply chuckled. Leigh slid back into unconsciousness but kept resurfacing that endless night to discover Marsalis violating her limp body. Finally, she opened her eyes to an apartment filled with late-morning light.

"Good morning," Marsalis said, smiling and leaning in for a kiss; Leigh, stunned, kissed him back. "I had a wonderful time last night. I hope you did, too," she says he told her, staring into her eyes. Leigh felt groggy and confused as she pulled on her jeans. So when Marsalis walked Leigh to her car and suggested they get together again, Leigh heard herself say, "Sure." She was certain she hadn't gone to bed with her date of her own volition—and that she couldn't possibly have blacked out after barely three drinks—but her certainty was softening in the face of his chivalry. Am I reading the situation wrong? Leigh wondered as she drove herself home. Would a rapist act this nicely?

Baffling as her experience seemed on that day in February 2005, Leigh was only the latest woman to struggle with the same confusion. Because Jeffrey Marsalis wasn't really an ER doctor looking for love. He was an unemployed paramedic and nursing-school dropout whose true profession, prosecutors assert, was full-time predator. Investigators would discover 21 women who claimed Marsalis drugged and raped them—many listed in a file on his computer called "The Yearly Calendar of Women." Authorities suspect his true tally is far higher. "Any woman was potential prey," says Philadelphia special prosecutor Joseph Khan. "Plenty of women were attracted to him, but this guy was aroused by the very idea of nonconsent."

As Leigh drove home that morning, she had no idea what lay in her future: that she would join 9 of those 21 accusers to face Marsalis in Philadelphia courtrooms over the course of two trials, telling nearly identical stories of assault. They would be 10 educated, professional women versus a demonstrated liar—a man who had pretended to be a doctor, a CIA employee, even an astronaut—whom a court-appointed psychologist would decide met the legal definition of a "sexually violent predator." And yet the most remarkable thing about both trials wasn't the way they exposed the alleged tactics of a serial date rapist. It was that despite the outrageousness of the accusations against Marsalis, the testimony of 10 women wasn't enough to get a single rape conviction against him. The verdicts in these cases would be far lighter than his accusers sought—and victims' advocates say the outcome reveals a disturbing truth about the justice system. Nationwide, despite all the legal advances of the past three decades, little has changed for women who report a date rape. Because in far too many instances, juries don't believe date rape exists.