What haunts them most, on their many sleepless nights, is the unanswerable question: "What if?" What if Shannon Schieber's brother Sean had visited her that evening? "He was going to stay the night in her apartment," says their father, Sylvester (Syl) Schieber. "But then Shannon called and said, 'I'm studying. Why don't you wait until morning?' " Or what if Shannon's cries for help had been handled differently? "What if a neighbor had broken down her door, or police?" her mother, Vicki, wonders. "The 'what ifs' can drive you crazy."

It has been nearly one year now that the Schiebers have been in agony over the unsolved murder of 23-year-old Shannon. A passionate and popular doctoral student at the University of Pennsylvania's Wharton School, Shannon was a day away from returning to her parents' Maryland home for spring break last May 7. But that afternoon she was found nude and strangled in her second-floor studio apartment in an upscale section of Center City, Philadelphia. "I've handled many homicides, and we strive to solve each case," says Lt. Kenneth Coluzzi, head of a six-person task force investigating the murder. "But certain cases touch you more than others. There's no telling how far she would have gone in life."

What makes Shannon's murder all the more unsettling is that she might still have been alive when police arrived on the scene—and the killer might still have been in her apartment. It was 2 a.m. when Schieber's neighbor Parmatha Greeley was awakened by screams of "Help me! Help me!" He ran to her apartment, pounded on the door and shouted that he was calling police. "I just heard like a choking sound," he told the 911 operator. Within seven minutes two policemen arrived. They knocked on Schieber's door, received no answer, checked around the building, then left, having advised Greeley and other neighbors against breaking down the door themselves. Instead, the cops said, "Call 911 if you hear any other noises." But no one would hear from Shannon again.

"The hardest thing to accept," says Syl Schieber, 52, "is that our daughter did everything she could to call for help. Think if it was your daughter calling out for help and the police just walked away." Last October the Schiebers filed a highly unusual lawsuit against the city of Philadelphia and the two officers, charging them with "an act of deliberate indifference and reckless cruelty"—in essence, failing to respond aggressively enough.

Philadelphia Police Commissioner John Timoney said at the time that the officers "acted appropriately given the circumstances." While standard procedure in such cases is in dispute, it appears the police left because they neither heard screams themselves nor saw any signs of a break-in. Investigators later revealed that a serial rapist who had previously attacked two women near Schieber's apartment is the main suspect in her murder. (There is no evidence she was raped, but semen found on her bedspread provided a DNA link to the rapist, who is still at large.)

The older of two children born to the Schiebers in Columbia, Md., Shannon showed great promise from the time she spoke her first words—"I see the school"—at 9 months. "She didn't like to sleep," says Syl, a vice president of a human-resources consulting firm. "We had to drive her around in our Volkswagen until she fell asleep."

Shannon, it seemed, was always too busy learning. "She'd read with a flashlight under the covers when she was in second grade," says Vicki, 54, an executive director of a trade association. In high school, Shannon earned a 4.0 grade-point average while indulging her passion for horses and helping to renovate rundown homes in Washington, D.C.

She graduated from Duke University—with a triple major in math, philosophy and economics—in just three years, but even more impressive was her capacity for friendship. She often spent hours with other students who were depressed or needed help. "She was just so kind," recalls Duke math professor Margaret Hodel. "She'd leave meals for people and give them little poems and gifts."

After college, Shannon took an accounting job in New York City before accepting a full scholarship to study finance and insurance at the Wharton School in 1997. Despite a grueling workload, she found time to teach economics to inner-city students. "She could really relate to them," says Sister Denise Mollica, a teacher at West Philadelphia Catholic High School. "We called her 'our Shannon.' " Indeed, "a lot of people would say that she was their best friend," says Benjamin Croituru, a student at Wharton. "She had this gift to make people feel better."

Yet Shannon herself felt isolated and unsafe at Wharton. For two months, she had been followed and threatened by a student (police have eliminated him as a suspect), and someone had tried to break into her car. "She didn't like Philadelphia," says Tomeka Hill, a friend from Schieber's undergraduate days. "She wanted to transfer to Duke."

On the afternoon of May 6, Shannon met with a school official to discuss ways to make doctoral students feel more integrated into campus life. Afterward, she returned to her apartment and called her brother, who was due to drive up from Washington, D.C. "She told me she wouldn't be able to go out as we planned," says Sean, now 23 and teaching English in Spain. "So I told her, 'You study tonight. I'm going to stay here.'

The next day, when Shannon failed to meet Sean at Wharton, he drove to her apartment and noticed from the street that her second-floor balcony door—which had been closed when police arrived the previous night—was open. In a panic, Sean and a neighbor broke down her front door. "I walked in and saw my sister's body on the bed," says Sean. "She had bruises on her face, and her eyes were just staring. It looked like she was staring at me."

One year later the image is still fresh in his mind. "I've had flashes of intense anger, then intense sadness,"" he says. "It's a rocky emotional state." Back in the Schiebers' redbrick home in Chevy Chase, Md., Syl and Vicki battle nightmares as they cling to their daughter's memory. "It's just so senseless," sighs Vicki, flipping through a scrapbook packed with pictures of Shannon. Try as they might, though, to focus on her remarkable 23 years, they cannot help but dwell on her terrible last hours. "Shannon was a good person who went out of her way to help almost anyone," says Syl. "The one time she needed help, the system didn't work."

Alex Tresniowski
Jane Sims Podesta in Chevy Chase and Matt Birkbeck in Philadelphia

  • Contributors:
  • Jane Sims Podesta,
  • Matt Birkbeck.