Coffee cup DNA solved Pennsylvania cold-case murder of Lindy Sue Biechler

The break in Lindy Sue Biechler’s killing came from something almost impossible to predict: a coffee cup tossed in a trash can at Philadelphia International Airport. That cup carried DNA that finally connected investigators to David Sinopoli, ending a 47-year search for the man who killed the 19-year-old newlywed in Manor Township, Pennsylvania.

Biechler was found dead on December 5, 1975, in her Spring Manor apartment complex home on Kloss Drive in Millersville. Prosecutors said she had been stabbed 19 times in the neck, chest, back and abdomen. A knife from her own kitchen was found in or on her body, and a tea towel was wrapped around the handle. The case became Lancaster County’s oldest cold case homicide, and for decades it sat in the backlog of shattered leads, false starts and dead ends.

Investigators did not give up, but the tools available to them kept coming up empty. DNA from semen on Biechler’s underwear was submitted to CODIS in the late 1990s and produced no match. Over the years, detectives and state police continued digging, conducting roughly 300 interviews and working through a long list of people who might have fit parts of the puzzle.

The turning point came in 2020, when CeCe Moore and Parabon NanoLabs took over the genetic genealogy work. The profile built from DNA tied the killer’s family line to Gasperina, Italy, in Calabria, narrowing the suspect pool in a way old-school investigation alone never could. That family-tree work mattered because it gave detectives a direction, and once they had one, they could test it against real-world surveillance.

On February 11, 2022, investigators covertly collected DNA from a coffee cup Sinopoli used and threw away at Philadelphia International Airport. They compared that DNA with crime-scene evidence from Biechler’s clothing, and the match helped confirm what genealogy had pointed toward. Lancaster County District Attorney Heather Adams announced Sinopoli’s arrest on July 18, 2022. He was 68 at the time.

Sinopoli later pleaded guilty on October 19, 2023, to third-degree murder, aggravated assault and burglary, and he received a sentence of 25 to 50 years in prison. He was 69 at sentencing. For a case that had outlasted so many investigators, the final answer came not from a dramatic confession or a fresh witness, but from a coffee cup thrown away after the fact, then turned into proof.