In the past three months, Luis Arroyo has asked himself the same question at least one thousand times.
"Why didn't I go answer the knock at the door that night? Why couldn't it have been me instead of Laura?"
On June 19, 9-year-old Laura Arroyo was watching television with her mother in an upstairs bedroom when she dashed downstairs to answer a knock at the front door of her family's San Ysidro condominium.
Arroyo remembers his daughter yelling, "I'll get it," as she ran to answer the knock.
It was about 9:10 p.m., and the last time that Laura's family saw her alive. The child's parting words still ring inside Arroyo's head as part of an interminable nightmare.
Incredibly, nobody--including the Arroyos--in the well-tended, normally safe row of condominiums, which are heavily populated with children, heard or saw anything.
When they realized 10 minutes later that Laura was gone, her anxious father and other family members drove around the area, looking for his missing daughter. While some family members searched, others quickly reproduced 300 flyers with Laura's picture and passed them out in the darkness.
But their efforts proved hopeless.
Two women reporting for work the next morning discovered Laura's body about 6:30 a.m. The killer or killers had dumped the body on a sidewalk, 5 miles away from the Arroyo home, in front of a bayside industrial complex in Chula Vista.
Police said that Laura, who was still dressed for bed, with bare feet and in her pink night clothes, was bludgeoned about the head and stabbed repeatedly in other parts of her body.
More than three months later, there have been no arrests. However, Chula Vista detectives said last week that they have been sifting through "a fair amount" of leads and forensic evidence, some of which is being analyzed by the FBI crime laboratory in Washington.
Although the investigation has taken a painstaking course, police are confident of solving the case, said Detective Wayne Maxey. Investigators were unwilling to discuss specifics, such as motive, but Maxey said detectives "are keeping close tabs on people we're interested in."
Meanwhile, the Arroyo family remains haunted. Arroyo and his wife, who is also named Laura, visit their daughter's grave three or four times a week, including every Sunday after they attend Mass.
The couple's two sons, Jaime, 11, and Luis Jr., 10, have struggled to adjust to their sister's death. Other students at Nicoloff Elementary School, where Laura was a third-grader, still point at the boys and ask them about their sister's death, Arroyo said.
"Our lives have been changed by this," said the 32-year-old tow truck company worker. "The boys' schoolwork has suffered. They are now afraid to play outside and spend most of their time indoors. They're afraid to answer the door."
Friends and acquaintances said that Arroyo has been wracked by unimaginable grief over Laura. In a recent interview, tears welled in Arroyo's eyes as he discussed his daughter's death.
He has gone through periods when he blamed himself for not doing enough to protect Laura, Arroyo said. His daughter was taken away while he was bathing Jaime and Luis Jr.
If only he had bathed his sons earlier, he would have been able to answer the door. If he had answered the door, Laura would still be alive, Arroyo has told himself over and over. But no matter how many times he questions himself and replays the events of that tragic night, Arroyo comes to the same conclusion:
"All Laura did was answer the door. How many times do people do that every day? It's one of those things that everyone does instinctively. I mean all she did was answer the door. Why should you expect to find danger in that?"
John Clark, Arroyo's employer at J.C. Towing in Chula Vista, said the death overwhelmed Arroyo.
"At the beginning, he would go to the cemetery every single day, during his lunch hour and after work," Clark said. "He would spend four or five hours at Laura's grave. He still sleeps with his daughter's picture beside him, and also sleeps in her room. Laura's room has remained untouched."
The case took a bizarre twist in July, when thousands of people said they saw Laura's image on a blank billboard near the corner of Broadway and Main Street in Chula Vista. The apparition was seen only at night, when the billboard was lighted.
Chula Vista police said that up to 30,000 people were coming nightly to view the billboard. Many believers said they saw Laura's face in the shadows cast by the lights on the white screen.
One night, the owners of the billboard, Martin Outdoor Advertising, turned off the lights. But, several hours later, because of what Martin officials said was a malfunction in a timing device, the lights came on automatically.