July 23, 2008— -- Denise and Nathan Lee were only teenagers when they met four years ago. Denise, then 17, was still in high school, but was also taking college courses at the same community college that Nathan, then 19, was attending. When Nathan saw Denise, it was love at first sight.
"I know it sounds cliché, but I mean, we really knew right away. I mean, we were two peas in a pod. We were as happy as you could be," Nathan said.
But that happiness came to a tragic end in January, when Denise was kidnapped and murdered. Her death could have been avoided, Nathan believes, if police had not mishandled crucial 911 calls that they received.
The two got married and soon after had their first son, Noah, in 2006. In July of last year, they had their second son, Adam. Despite being so young, Denise and Nathan were making things work. Denise stayed at their home in North Port, Fla., with the kids while Nathan worked hard to support his family.
"We had two beautiful kids and were just, you know, just livin' the American Dream," Nathan said. Until suddenly, one day, the dream was destroyed.
Nathan remembered Jan. 17 to have been a regular day -- he went to work early in the morning before Denise was up with the two boys. The last time they spoke to each other was around 11 a.m. He tried calling her cell phone on his way home around 3 p.m., but couldn't get a hold of her, even though he tried several times.
At 2:30 p.m., just an hour before Nathan would get home, their neighbor, Jennifer Eckert recalled peeking out of her blinds and seeing "a green Camaro going up and down the road." She said she saw the car pull into the Lee's driveway and noticed a man sitting in the driver's seat.
When Nathan got home around 3:30 p.m., he said he found his two sons alone.
"It was within 10 minutes that I really knew that something's not right," Nathan said. He sensed his 21-year-old wife was possibly in serious trouble. As he searched the home and found her cell phone and purse, he questioned his 2-year-old son about where his mother was.
Nathan said he became very nervous and started to "lose it." He then made the first 911 call that he believes could have saved Denise's life. He was stunned, left to sit on the porch and wait, paralyzed as police searched their home for any clues to where Denise might have been.
Then, there was a break in the case: Denise, herself, called 911.
At 6:14 p.m. Denise, the daughter of a sheriff's deputy, somehow got hold of her alleged kidnapper's cell phone. According to a North Port police report, operators listened to her pleading helplessly with her alleged captor for about six and a half minutes.
Denise's father, Rick Goff, heard the recording, which has not been released to the public.
"The dispatch is asking questions and she's like making it sound like she's talking to him ... but she's really answering dispatch questions. 'Where do you live' and things like that," Goff said.
But before police could get a fix on the location, the call was lost. However, police said they were able to determine that the cell phone belonged to a North Port man named Michael King, a 36-year-old unemployed plumber.
Nathan characterized the call from his wife as "the first step to getting her back."
But by the time the police had this crucial piece of information and rushed to King's home, it was too late. Neither King nor Lee was there. Police found the house empty except for disturbing traces in the bedroom: a child's blanket and duct tape with long brown hair stuck to it.
Family members believe there was a second and perhaps better opportunity to save Denise Lee, when the alleged kidnapper stopped at his cousin's house to borrow a shovel and a can of gas. Harold Muxlow, King's cousin, later told North Port police that King told him he needed those items because, "his lawnmower was stuck in a ditch and out of gas."
Muxlow said he even witnessed a tied up Lee screaming, "call the cops" and struggling to get out of the back seat of his cousin's car. In the end, he failed to call the police and, instead, called his 17-year-old daughter, Sabrina Muxlow, to tell her what he'd seen. She, in turn, immediately called 911.
At 6:23 p.m., Sabrina's call reached the Sarasota County, Fla., 911 Call Center. Muxlow told operators that her father saw a girl tied up and that she "came out of the ... car and my dad's cousin went and put her back in the car when she got out." She also described the car as "a green Camaro."
In her first media interview, Sabrina Muxlow told ABC News that she knew calling 911 was the right thing to do.
"It's common sense. ... She needed help, was yelling 'Help.' If somebody needs help, then you get help, you don't stop and think about it," Muxlow said.
But by the time police got the call, King had already left his cousin's house with the shovel, gas can and a flashlight, and Denise Lee still fighting for her life.
As night began to fall, at least three known motorists, who have spoken to the police, witnessed Lee struggling in the back of King's car. Two of them are speaking publicly for the first time, and asked ABC News not to identify them by name.
One man said that he saw Lee, "slamming on the windows with her palms really hard.
"It just looked like she was trying to break them out ... and shaking her head back really violently, back and forth," he said.
Both eyewitnesses said they had second thoughts about calling 911 because they didn't want to get involved in what they thought was a domestic dispute.
The first man admitted that he "actually dialed the number but didn't hit send on it."
The final images of Lee stuck in the back seat of the car haunt him every day. "It made me sick to my stomach that I hadn't done what I should have done, made the phone call," he said.
Jane Kowalski, a computer consultant from Tampa, saw Denise struggling in the back seat of the green Camaro. She was probably among the last people to see her alive.
Kowalski still vividly remembers the night of Jan. 17, when she was driving down U.S. 41 in North Port. She was driving a small car and was talking to her sister on her hands-free device. Her window was cracked open so she could get some fresh air. She stopped at a red light and a car pulled up next to her.
All of a sudden, she heard loud noises. They were so loud that her sister on the other end of the cell phone was able to hear the commotion. At first, Kowalski thought it was a child screaming.
"It was a very high-pitched scream, and it was unlike any type of scream I'd ever heard in my entire life," Kowalski said. She said she even made eye contact with King. "He's looking at me, and as he's looking at me, he's pushing down in the back seat of his car.
"After he does that, a hand comes up from the back seat and is slapping on the window as loud as can be," she said.
After witnessing this, she immediately called 911 between 6:30 p.m. and 6:39 p.m. and was connected to the Charlotte County 911 Call Center. She told the operator exactly where King's car was driving, but described it as a blue Chevrolet Camaro. She repeatedly told the operator that she heard screaming, crying and banging on the passenger-side window, as if this person wanted to get out.
At that very moment, deputies were nearby, some on foot with police dogs, some in patrol cars, and there was even a helicopter. But Charlotte County dispatchers failed to tell patrol cars on the street what they learned from Kowalski: that there was a Chevrolet Camaro at a precise location with screaming person in it, within their reach.
Sheriff John Davenport of the North Port Police Department described the breakdown of this basic police procedure as a "missed opportunity."
"This 911 call, one dispatcher thought the other had sent it out, the other thought the other one had sent it out, and they didn't send it out," Davenport said.
Less than three miles away from where Kowalski made the last 911 call, Denise Lee was shot to death. King was apprehended that same night by a Florida Highway Patrol trooper on Toledo Blade Boulevard, trying to enter Interstate 75 in Sarasota.
King was initially booked into the South County jail on one charge of kidnapping. He refused to provide any information about whether he was involved in Denise Lee's disappearance and, instead, told investigators he was the victim along with Lee.
But an incredible revelation was made while searching King's green Camaro. Apparently, afraid that her death was imminent, Lee left clues for the North Port police investigator in the back of the car. They found blond locks of hair and a ring, which Nathan said belonged to his wife.
"It was a ring that I gave her on our first Valentine's Day ... It took me less than a second to confirm that it was hers," Nathan said.
Two days later, Lee's body was found in a shallow grave near Interstate 75 and Toledo Blade Road. Authorities say they also have DNA evidence that King sexually assaulted her.
On Jan. 23, Sarasota County prosecutors charged King with the abduction and murder of Denise Amber Lee. He pleaded not guilty.
It still remains unclear why he allegedly chose to terrorize Lee. King's ex-girlfriend, Jennifer Robb, said she did not know if or how King and Lee were connected.
"I couldn't see him just randomly picking somebody," Robb said. Despite the accusations, Robb has stood by King's side and said she never saw him act violently.
"He was a good person, never had any problems, he helped raise my kids. ... I mean, he was a regular family guy," Robb said. "It was hard to believe, you know, without evidence, that he could do something like that. ... It was hard to sit there and believe that he could just do it."
In the end, who is to blame in Lee's murder? Davenport says it is wrong to assume the botched 911 calls cost Lee her life.
"Frankly, my own opinion, and it's only mine, I don't think it would have changed the outcome one bit, simply because we had people in the area looking for the exact vehicle," Davenport said.
He stands by his dispatchers and said it was a tragedy for his department, especially because Lee's father has worked in the Charlotte County Sheriff's Office for more than 20 years. The dispatchers who failed to relay the 911 call were disciplined. One was suspended for 60 hours, the other 36 hours, and both were ordered to take 12 hours of remedial training.
Meanwhile, Nathan has moved out of their North Port home with his two boys. He tries to live for the happy moments he should have had with his wife and family.
"I was supposed to spend the rest of my life with her. And ... there wasn't a doubt in my mind, wasn't a doubt in hers. The best four years of my life, I'm sure. For my whole life," Nathan said.
Nathan wants the death penalty for King and intends to sue Charlotte County for mistakes he says the sheriff's department made on the day his wife died.
"If I was in that situation ... I don't know what I would have done," he said. "She did everything she could. Denise did everything in her power to save her life."
Visit the Denise Amber Lee Foundation for more information about her story.