WESTBURY, N.Y. (CBSNewYork) – Police in Nassau County said Thursday they’ve cracked a cold case, the murder of a Westbury woman 15 years ago.

As CBS 2’s John Slattery reports, it was modern technology that helped solve the mystery.

He must have been surprised that 15 years after the killing, he ended up arrested. Paul Sampson, 65, of Hempstead was charged with a murder that had gone unsolved since he was 50.

“DNA was the key to the door that opened up this case,” said Nassau County Police Lt. John Azzata.

The victim was 60-year-old Vilma Portillo, a single mother of eight who worked seven days a week to support her family. Portillo worked as a cleaning lady inside a Westbury building that used to be a pharmaceutical company.

On Sept. 14, 1995, as she came out here to her car, she was robbed and fatally shot.

Police had little to go on. Questioning employees went nowhere. But then, just recently, they caught a break.

“We had a piece of evidence with DNA on it and that DNA ultimately matched to Mr. Sampson,” Lt. Azzata said.

Police to support her large family Portillo had a side job of selling clothing at flea markets. She did business with Sampson and he knew when she got paid.

“In addition to her collecting her salary at her company, she would also collect from people who bought clothes on credit, and that’s the reason she had that amount of money on her that day, which was approximately $4,000,” Lt. Azzata said.

Investigators said because Sampson was a convicted felon his DNA was in a database.

Police said the case points up not just the value of DNA evidence, but the perseverance of detectives who submit old evidence for testing.

Police said Sampson has a record dating to 1964, including a manslaughter conviction in 1981.

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