On a Friday night in 1975, 19-year-old Lindy Sue Biechler returned home from the grocery store to her Manor Township, Pennsylvania, apartment. What should have been an ordinary evening ended in a brutal killing that would haunt Lancaster County for decades.
Relatives who stopped by the newlywed’s apartment made the devastating discovery. Biechler was dead, with a butcher’s knife embedded in her neck; its handle had been wrapped in a tea towel.
Investigators found that she had been stabbed 19 times in the torso, chest and back. Her shirt had been pushed up, and her pants were unfastened, details that added to the disturbing nature of the crime scene.
“It looked like she would have been attacked as soon as she opened the door,” Lancaster County Detective Larry Martin said on the June 20 episode of Philly Homicide. “She actually fought for her life.”
Who Was Lindy Biechler?
As the investigation later focused on David, detectives uncovered connections between him and Biechler. At one point, he had lived one floor above Lindy Sue, and the two had attended the same middle school in Lancaster County.
On the surface, David seemed to have led an unremarkable life. He was a married father who worked for several printing companies, and his first wife characterized their divorce as amicable.
Detectives eventually began watching David in the hope of discreetly obtaining a DNA sample. But the effort was complicated by the onset of COVID-19 restrictions and stay-at-home orders, which made surveillance far more difficult.
The case took a significant turn in February 2022, when the FBI learned that David and his wife were planning to travel through Philadelphia International Airport for a vacation.
On that day, detectives headed to the terminal and found the couple sitting at a coffee shop. When David threw out their empty cups, Martin swiped them from the trash.
“I was flying high,” he recalled. “I was really excited.”
More than 46 years after Lindy Sue was murdered, experts were able to match David’s DNA to the profile of the killer—with odds of 1 in 10 trillion.
In July 2022, David was arrested as he walked down the driveway of his house to retrieve his morning newspaper.
He pleaded guilty to third-degree murder, aggravated assault and burglary in October 2023 and was sentenced to 25 to 50 years in prison.
David never revealed his motive.
“I’ve always wanted to know the ‘why’ but he’s never told me and probably never will,” said Phil. “He sent me an apology letter that had one sentence in it that said, ‘I’m very, very sorry’—and that was it. To me, David Sinopoli is only sad because he got caught.”
