An immigrant in New York without family nearby, Reyna Marroquin had simply fallen through the cracks.
"I think it would be a terrible thing for a parent to go all those years and never know what happened to her daughter," Detective Robert Edwards observed.
With the grisly discovery of her body 30 years later, Detective Edwards looked first at that house on Long Island.
"Well, we started to go backward with the prior owners of the house," he said. He went as far back as the second owners, the Ebbins. Detective Edwards recalled: "And they said, 'Nope, that was there from the time we moved in; it was there since the time we bought the house."
So, Edwards focused on the man who had sold the house to them. "Howard was a very tall, good looking, distinguished businessman," Arthur Ebbin recalled.
Then the detective stumbled across a remarkable coincidence linking that man to Reyna Marroquin. "We found out that he worked for a plastics company where they made plastic flowers. Inside the drum, we found the stem of a plastic flower," Detective Edwards said.
The trail eventually led police to a retirement community in Boca Raton, Fla., and to Howard Elkins. In 1969, Elkins had owned the plastics factory where Reyna Marroquin worked and the house where her body later was found.
"I think he was a little taken aback when we rang his doorbell," said Detective Edwards.
Elkins, a father of three, lived with his wife, enjoyed sailing and was known as a pleasant but private individual. "He came across as a person who is very comfortable with himself,...very glib," the detective recalled.
He denied knowing anything about any drum. "He could look you right in the eye and tell you, 'I don't have any knowledge of this,'" Detective Edwards said.
Although calm at first, Elkins became increasingly nervous as police pressed for details.
"He wouldn't answer readily; he would just stare at you when you asked him a question, and these were hard questions," Detective Edwards recalled.
He finally admitted to having had an affair with an employee, but claimed he couldn't recall specifics. "He didn't remember her name; he couldn't give us a physical description at all," Detective Edwards said.
But the evidence against Elkins was mounting, with painstaking forensics work paying off with startling clues.
Elkins couldn't explain why his name was in the address book found in the barrel.
"There came a time when we asked him if we could take a DNA swab of the inside of his mouth, and he refused that," Edwards recalled.
Since Reyna Marroquin had been pregnant when she died, the DNA could determine if the unborn child as Elkins' and give a possible motive for the crime.
"He's a married man, having an affair with a woman that he works with in a factory and now she's pregnant," Detective Edwards suggested.
The detective was starting to feel that the murder of Reyna Marroquin some 30 years ago soon would be solved.
Edwards recalled meeting with Elkins one day: "We made it very evident to him that we were going to forward with this, that we were going to attempt to get a warrant for his DNA. And I think that he felt that at that time he was going to be had."
Then the case took an unexpected turn.
"The whole day went by before the warrant was issued. We called into the office... and we were told that the Boca Raton police were looking for us," Detective Edwards said.
Twenty-four hours after Detective Edwards left Elkins, he bought a shotgun at a Wal-Mart, went to a neighbor's garage, and shot himself to death.
"He didn't have a lot of options," Detective Edwards reflected. "When he was arrested, he was a man of 71 years old. What was he going to do - spend the rest of his life in prison for a crime that had happened 30 years before? I don't know what went through his mind, but obviously it was something he didn't want to face up to."
At Elkins' autopsy, police got his DNA. The probability of paternity was determined to be 99.93 percent.
And on that note from Reyna Marroquin's address book, they found even more evidence that her affair with Elkins may have led to her death. One can make out the words "don't be mad . . . I had to . . ."
Other letters could be made out as well. "There's a T, an O, an L and a D," Detective Dennis Ryan said.
Recited Detective Fiertner: "Don't be mad I told the truth."
"We found a motive, we found a suspect, and I think the case is closed at this time," said Detective Edwards.
But exactly what happened that winter day three decades ago?
"I think he comes to the apartment, takes her out of there, I think he takes her to the factory. There's no doubt in my mind that he's the one that killed this woman," said Detective Edwards.
"I don't think he knew what to do with her. I think he had a plan that he was going to package her up and perhaps get rid of her. But once the package was completed, it was just too heavy for one person to move, and I think at that time he was stuck," he added.
For her loved ones, after 30 years, details don't seem nearly as important as the fact that Reyna Marroquin is finally back home.
"I feel happy that finally she rests in peace in El Salvador where she belongs," said friend Kathy Andrade.
"Now I know she's with me. She came flying like a dove back to her home," said Grandma Marroquin.
"My sister is still alive with us; we will never forget her," said Dora Marroquin.