PLANTATION, Fla., Sept.18, 2008— -- One evening in April, after Olidia Kerr Day's relaxing day at the beach with her children, her family was interrupted by a knock on the door shortly before dinner.
Her son Edward Kerr, 24, opened the door, assuming it was his mother's boyfriend, Jesus Sosa. Instead, Carlos Cevallos walked in.
Kerr Day, 45, had met Cevallos, 48, several weeks earlier at the supermarket, where he worked as a meat clerk. Although they became friendly and she hired him to do handyman work around her house, it quickly became apparent to Kerr Day and her children that Cevallos wanted a romantic relationship.
"She tried to be his friend, and then she realized that she couldn't just be friends with him because he wanted more," said Kerr Day's 20-year-old daughter, Elizabeth Kerr, who believes Cevallos was stalking her mother. "A few days before, my mom said, 'Cevallos just called me up and said, "I have a gun."' She was very afraid of him."
Now, the man that Kerr Day believed had a gun was at her front door unannounced, and practically forcing his way in.
Kerr Day, who was in the shower, instructed her son Edward Kerr to make Cevallos leave. But it was too late: Cevallos saw Kerr Day and made his way to the bedroom, slamming the door behind him.
"I'm worried so I begin to pound on the door and I tell her, you've got five seconds to tell me everything's OK and open this door before I break it in," Edward Kerr told ABC News. "At this point, she starts speaking in Spanish to him, and maybe five seconds, six seconds later, she comes out."
Kerr Day had done something very brave. In Spanish, she promised Cevallos that he would get an opportunity to talk to her, but not in the house and certainly not in front of her kids. She ran towards the door, only telling her son to lock the house. Cevallos marched out behind her and her puzzled boyfriend, Sosa, followed unalarmed -- until he saw them get in separate cars, with Kerr Day looking panicked.
"There was something wrong," said Sosa emotionally. "She rolled the window down, and said, 'Jesus, he had the gun to my head. He's gonna kill me.'"
Fearing Cevallos would kill them both right then and there, Sosa decided not to get in the car with Kerr Day, opting instead to jump in his van and follow them. But his rickety van had trouble starting, so Kerr Day sped away in her car with Cevallos right on her tail. Sosa tried to keep up with the chase but ended up losing them. In her car, Kerr Day frantically called 911.
"Listen please. Don't hang up and listen to me, I've been taken out of my house at gunpoint. I'm gonna head to the police station," she told a 911 call taker. "I was able to lie to him, and I'm going to go inside."
"Ma'am, ma'am, ma'am, you need to slow down because I don't know where you are," replied the 911 call taker.
It turns out her desperate call for help had gone to the wrong police department because she was on a cell phone and the closest transmission tower sent her call to the police in the adjacent town of Sunrise, Fla., not Plantation, Fla., where she lived.
It took a minute of valuable time to transfer the fleeing mother to Plantation police.
But things still didn't get any easier for Kerr Day. The 911 call taker for Plantation insisted that Kerr Day provide her with an address, ignoring Kerr Day's numerous requests for the location of the police department.
Kerr Day was able to make it to the police parking lot on her own, without any help from the emergency call taker, but there she ended up blocked by an iron gate.
With nowhere to go, Kerr Day sat in her car, still frantically begging for help and hoping for police to arrive. Her lifeline began to sound frustrated.
"Stop yelling because I can't help you if you're yelling," the Plantation call taker said.
"I'm stuck now. He's going to kill me," said Kerr Day, who had been speaking with the Plantation call taker for one minute and 34 seconds.
Those were her last words. The chase ended with her muffled screams -- literally at the police department's front door.
Surveillance cameras captured Kerr Day running out of her car with Cevallos behind her, gun in hand. He shot her in the back and then again after she fell to the ground before he took his own life.
Kerr Day was rushed to the hospital but died on the operating table before her children were ever told about the shooting.
"We deserved that last moment to touch her body one last time warm," said Edward Kerr.
Cevallos had no real criminal record, just a DUI arrest years ago. He left behind a revealing suicide note in Spanish, in which he declared his devotion to Kerr Day.
"I've made a decision to put an end to my life next to my partner, Olidia," he wrote.
Police also found a receipt from a local gun range where Cevallos went for target practice the day before the bloodbath. He had 30 rounds of ammunition in his car.
Kerr Day's family was further devastated when they heard the chilling tape of their mother's 911 call, where for more than three and half minutes Kerr Day could be heard begging for help. No attempt was ever made to send someone to her aid.
"The complete fear in her voice, it just didn't sound like her," said Elizabeth Kerr. "It sounded like a different woman."
Kerr Day's sister, Ada Perez, thinks the call taker's attitude, tone and line of questioning were completely uncalled for.
"I was so angry when I heard that 911 call," she said. "She's the one that did wrong, the 911 call taker at Plantation. She's just as much to blame for my sister's death as Cevallos is."
Plantation Chief of Police Larry Massey defended the actions of the 911 call taker.
"This is not a case of willful misconduct. I don't even think it's a case of professional negligence on the part of the dispatcher," he said in an exclusive interview with "20/20." "She had to handle a very difficult situation in an environment where she didn't know where the caller was. I wish things turned out differently, but I still stand behind the dispatcher. I think she did a reasonable job."
No one was disciplined in Massey's department as a result of what happened to Kerr Day. But after her murder, the chief ordered a complete overhaul of training and procedures in the communications center.
Kerr Day did everything she could to save herself and protect the most important things in her life -- her children, who she called her angels.
"She prevented a bloodbath. She was smarter than everybody in this case," said Edward Kerr. "She did everything right. She did their job for them. She took him to be arrested at the station."