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Pennsylvania Man Arrested In Woman's 1975 Murder After DNA Allegedly Links Him To Crime

Officials say they used DNA off a discarded coffee cup to link David Sinopoli to the murder of 19-year-old Lindy Sue Biechler, who was stabbed to death in her own home. 

By Jax Miller
A police handout of cold case victim Lindy Sue Biechler

Officials from Pennylvania's "Dutch Country" say they’ve arrested a man after DNA allegedly linked him to one of the “most notable unsolved cases” of the area.

Lindy Sue Biechler was 19 years-old when someone stabbed her to death at her apartment in Manor Township — 10 miles southwest of the city of Lancaster — on the evening of Dec. 5, 1975, according to the Lancaster County District Attorney’s Office. Although numerous attempts were made to find the culprit, authorities failed to definitively identify the person responsible for the young married woman’s murder.

On Sunday — more than 46 years after Biechler’s death — officials say they’ve identified 68-year-old David Sinopoli as a suspect in the case.

“Lindy Sue Biechler was 19 when her life was brutally taken away from her 46 years ago in the sanctity of her own home,” said Lancaster County District Attorney Heather Adams. “This arrest marks the beginning of the criminal process in Lancaster County’s oldest cold case homicide, and we hope that it brings some sense of relief to the victim’s loved ones and to community members who, for the last 46 years, had no answers."

Biechler was stabbed 19 times at her home shortly after returning from a grocery shopping trip between 6:45 p.m. and 7:05 p.m.. The grocery bags were still on the dining room table when the victim’s aunt and uncle found Biechler at around 8:46 p.m. and called the police.

One of Biechler’s own kitchen knives had been used in the attack and was still protruding from her neck when officers arrived. Someone had wrapped a tea towel around the wooden handle of the murder weapon, which had been used to stab the teenager in her neck, chest, upper abdomen and back.

The suspect’s semen was found on Biechler’s underwear.

The killer reportedly used two knives in the vicious assault — and the person believed to have been the killer left a footprint in the kitchen, according to Fox York affiliate WPMT.

A police handout of David Sinopoli

According to WPMT, Biechler’s husband was ruled out as a suspect and, within less than two months, police interviewed between 250 and 300 individuals about the case. Despite multiple law enforcement agencies working on the investigation — including the Manor Township Police Department and the Pennsylvania State Police — the case remained unsolved for decades.

Investigators were able to extract DNA from the semen in the victim's underwear 25 years later — in 2000 — and submitted it to federal databases, but no matches were returned.

In 2019, however, the recently-established Cold Case Unit within the Lancaster County District Attorney’s Office requested the help of Parabon NanoLabs.

Local investigators previously had success with the use of genetic genealogy by a private company in 2018, which resulted in an arrest in the 1992 murder of Christy Mirack —a case featured in Oxygen’s “Dateline: Secrets Uncovered.”

In the Biechler case, they first asked the company to help generate composites of the suspect, using the DNA to develop a profile based on phenotypes. Parabon helped experts create an image of a fair-skinned man with hazel eyes and dark hair.

In 2020, officials asked Parabon to conduct genetic genealogy testing, which “ultimately identified Sinopoli through his Italian ancestry as a possible person of interest.”

Investigators on Feb. 11 of this year then “surreptitiously” collected Sinopli’s DNA, which he left on a coffee cup he threw out at the Philadelphia International Airport.

Ultimately, experts determined in April that DNA from Sinopoli’s discarded coffee cup “had a match statistic around 10 trillion” with the semen found at the 1975 crime scene.

Returning to evidence collected from Biechler’s person, investigators examined two blood spots found on the victim’s pantyhose, which also allegedly yielded a match to Sinopoli in June.

Sinopoli was arrested at his Lancaster home on Sunday morning without incident, according to prosecutors. He was arraigned and remanded to the county jail without bail.

A motive in the case — as well as whether or not the suspect and victim knew one another — remains unknown.

“This arrest would not have been possible without the assistance of CeCe Moore and Parabon NanoLabs,” District Attorney Adams stated. 

The district attorney’s office also thanked those involved with the case “from beginning to end,” including the Manor Township Police Department.

“There has been a never-ending pursuit of justice in this case that has led us to identifying and arresting Sinopoli,” Adams continued. “Law enforcement never forgot about Lindy Sue, and this arrest marks the first step to obtaining justice for her and holding her killer responsible."

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