Ali Kemp seemed to lead a charmed life. The 19-year-old grew up in a loving home with her parents and two brothers in the idyllic setting of Leawood, Kan., a peaceful, tree-lined suburb just outside Kansas City. By all accounts, she was a remarkable young woman, who dreamed of someday going to Russia to work with needy children. But she never got the chance.
On an overcast day in June 2002, Ali lost her life in a moment of terrible, senseless violence. Even veteran police officers in the community claimed they had never seen anything like it before.
"I'd have to say that in my 35 years of experience it was probably the most horrific thing that could happen to a community like this," said Maj. Craig Hill of the Leawood Police Department.
Kemp had just finished her freshman year at Kansas State University, where she was an honors student, and was working as an attendant at a neighborhood pool, just four blocks from her family's home.
"It was a wonderful job, a neighborhood pool. And you would think the safest place in the world," her father, Roger Kemp, told "20/20" correspondent Don Dahler.
But that June day, when overcast skies left few people at the pool, Ali was randomly confronted by a man in the pool's pump room. Moments later, he would brutally beat and strangle her.
At around 3 p.m. she called her friend Laurel Vine to come keep her company during her shift at the pool. She then called her boyfriend, Phil Howes, on his cell phone. But Howes missed her call. "I wish I could have answered that, because maybe she was in trouble then, and was trying to get hold of me."
Nothing seemed out of the ordinary when Vine pulled into the pool parking lot. "I saw a man walking out. I presumed he was a maintenance worker. And I just kind of looked around and saw Ali's stuff there. I just assumed that she had gone to do something really quickly. And then I left and went home," she said.
Two hours later, when Ali's brother, Tyler, showed up to relieve her of her pool duties, he noticed her purse and cell phone on a table but no sign of his sister. So he called his father, who came over to help find her.
"I looked around the pool, went into the pool house and I went in. I didn't see anything. And then I just took a few more steps and then I found Ali. ... She'd been covered and her leg was sticking out. ... I threw back the cover and there she was," her father recalled tearfully.
Detective Joe Langer got the call, and arrived at the crime scene to find evidence of a violent struggle and a girl who'd been brutally beaten.
"She was fighting for her life and, unfortunately, lost that fight," Langer said.
When Vine heard the terrible news, she immediately thought about the man she saw earlier. "I thought, 'Oh, my God, I just saw her killer and I didn't know it,'" she said.
With a killer on the loose, the community was terrified. Forty detectives from the Kansas City area fanned out looking for leads.
The police asked Vine to sit down with a forensic artist and describe the man she saw.
Leawood's tiny police department was stretched to the limit. "They never left one stone unturned. They wanted to find this individual," Hill said.
But eight months passed and Ali's killer was still at large. Everyone was becoming increasingly discouraged.