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Here's what led investigators to charge David Sinopoli with killing Lindy Sue Biechler in 1975

Police were able to develop Sinopoli as a suspect thanks in part to information provided by the same DNA testing firm that helped break the Christy Mirack case.

LANCASTER, Pa. — A 68-year-old Lancaster man has been charged with the murder of Lindy Sue Biechler nearly 47 years after she was found dead in her Millersville-area apartment, law enforcement officials in Lancaster County announced Monday.

David Sinopoli, of the 300 block of Faulkner Drive, has been charged with criminal homicide in Biechler's murder, Lancaster County District Attorney Heather Adams said Monday in a press conference at Lancaster County Courthouse. 

Sinopoli was arrested without incident in his home on Sunday, Adams said.

He has been living in Lancaster for decades following Biechler's murder while investigators attempted to charge a suspect in the case.

Biechler was found dead in her Manor Township apartment on the night of Dec. 5, 1975. She had been stabbed 19 times in the throat, upper torso, and back after returning home from the grocery store earlier that evening. Relatives discovered her body at about 8:46 p.m., Adams said.

Investigators found blood outside the front door and entranceway, along with several other patches of blood on the carpet of the home. Her grocery bags were still on the table and there were signs of struggle throughout the home, police said at the time.

Biechler was found on the floor, lying on her back with a knife sticking out of her neck. The knife had a tea towel wrapped around the handle, investigators said. It matched the knives found in a knife block in Biechler's kitchen.

Manor Township Police, State Police, and numerous other law enforcement agencies have been investigating the case every since, questioning and clearing dozens of people over the ensuing decades. 

"The arrest is the culmination of decades of investigation by multiple agencies and more recently, the investigation conducted by County Detective Chris Erb, Larry Martin, and the extensive research they performed with the assistance of Assistant District Attorney Christine Wilson," Adams' office said in a press release.

The investigation was also aided by information provided by Parabon NanoLabs, the Virginia-based agency that helped break the cold-case murder of Christy Mirack in 2018. 

In September 2019, Parabon NanoLabs provided a composite sketch of the suspect in Biechler's case based on a DNA profile it compiled from evidence collected at the scene in 1975, Adams said.

The composites revealed characteristics of the suspect, including skin tone, eye color, and hair color, according to Adams. The sketches showed the suspect at ages 25 and 65.

In December 2020, Adams' office asked Parabon NanoLabs to proceed with further genetic genealogy analysis. 

Parabon's genetic genealogy research produced Sinopoli as a potential person of interest in the case, based on his Italian ancestry.

Investigators needed to collect a sample of Sinopoli's DNA to determine if it matched evidence taken at the scene in 1975. So, on Feb. 11, they surreptitiously collected a coffee cup Sinopoli used and discarded while at Philadelphia International Airport, according to Adams.

The coffee cup was submitted to DNA Labs International for testing, Adams said. In April, test results determined the DNA sample left on the coffee cup was a mixture provided by a single male contributor. The DNA was then submitted to Cybergenetics, a Pittsburgh-based laboratory that specializes in separating DNA mixtures.

Analysis by Cybergenetics determined the DNA on the coffee cup matched that of semen collected from Biechler's underwear at the scene of the murder in 1975. The match statistic was around 10 trillion, Adams said.

Detectives then consulted with a blood spatter expert to see if any blood left behind on Biechler's clothing would be consistent with having been left behind by a suspect, Adams said. The expert identified two blood spots left on the exposed part Biechler's pantyhose, and investigators submitted the spots to DNA Labs for testing.

The tests found the blood drops were consistent with the DNA profile left in Biechler's underwear.

"This arrest would not have been possible without the assistance of CeCe Moore and Parabon NanoLabs," Adams said. "We are incredibly greatful for the work that they do and their commitment to securing justice for victims and their loved ones.

"The Lancaster County District Attorney's Office also wishes to thank everyone involved in this case from beginning to end. There has been a never-ending pursuit of justice in this case that has led us to identifying and arresting Sinopoli.

"Lindy Sue Biechler was on the minds of many throughout the years. Certainly, law enforcement never forgot Lindy Sue, and this arrest marks the first step to obtaining justice for her and holding her killer responsible."

The case remains under investigation. Adams is asking anyone who was familiar with Sinopoli during the December 1975 timeframe to contact Lancaster County Detective Chris Erb at (717) 299-8100. 

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