On 13 July, the night of Rex Heuermann’s arrest, investigators collected the samples from Asa Ellerup at their Massapequa Park home.
Mr Heuermann was taken into custody on suspicion of murdering three women whose remains were found wrapped in burlap and dumped in a marshy area of Gilgo Beach on Long Island.
Court records show that the 60-year-old Manhattan architect was linked to the “Gilgo Four” murders through a tip about his pickup truck, a stash of burner phones, “sadistic” online searches and phone calls taunting victims’ families.
His DNA was also found on one of the victims, while his wife’s hair was found on the burlap of three of the four women he is connected to, according to Suffolk County prosecutors.
And now, the sources confirm the DNA that was extracted from those hairs match the cheek swab samples from Ms Ellerup. She has not been accused of wrongdoing in the case.
Ms Ellerup and the couple’s adult children Victoria Heuermann, 26, and Christopher Sheridan, 33, are said to have been blindsided by his shock arrest.
Court documents laying out the case against Mr Heuermann have stated that his family members were out of town at the time of the killings.
Ms Ellerup filed for divorce just six days after her husband’s arrest.
The Suffolk County District Attorney’s office has said DNA from Mr Heuermann’s cheek swab matched his genetic material found on a pizza box investigators recovered from the trash near his Manhattan office.
Mr Heuermann is accused of murdering Amber Lynn Costello, 27, Melissa Barthelemy, 24, and Megan Waterman, 22.
He has also been named the prime suspect in the murder of Maureen Brainard-Barnes – who was last seen alive in early June 2007 in New York City.
The four victims, together known as the “Gilgo Four”, all worked as sex workers and disappeared after going to meet a client.
Their bodies were found in December 2010 within one-quarter mile of each other, bound by belts or tape and some wrapped in burlap – all dumped along Gilgo Beach.
In total, the remains of 11 victims were found along the shores of Long Island in 2010 and 2011, sparking fears of one or more serial killers.
The case began back in May 2010 when Shannan Gilbert, a young woman working as a sex worker, vanished after leaving a client’s house on foot near Gilgo Beach. She called 911 for help saying she feared for her life and was never seen alive again.
During a search for Gilbert in a dense thicket close to the beach, police discovered human remains. Within days, four victims had been found.
By spring 2011, the number of victims rose to 10.
Gilbert’s body was then found in December 2011. Her cause of death is widely contested with authorities long claiming that it is not connected to the serial killer or killers but that she died from accidental drowning as she fled from the client’s home.
However, an independent autopsy commissioned by her family ruled that she died by strangulation and her family continues to believe she was murdered.
No charges have been brought in connection to the other victims also found along the shores.
Investigators are continuing to work to determine if Mr Heuermann is also linked to any of the other victims – while law enforcement officials across the country are probing cold case murders for any potential ties.
Mr Heuermann has pleaded not guilty to first and second-degree murders charges.