Two victims of the 9/11 terrorist attack were identified Tuesday after 20 years of DNA analysis, according to the New York City Office of Chief Medical Examiner (OCME).

The victims were identified using new technology and advancements in DNA science developed and applied at OCME. Dorothy Morgan is the 1646th identified victim and a man whose family has decided to keep his name unknown is the 1,645th victim.

Morgan was from Hempstead, New York, and worked as an insurance broker in the north tower.

The victims were identified last month just days apart from each other and were the first identifications since 2019.

“Twenty years ago, we made a promise to the families of World Trade Center victims to do whatever it takes for as long as it takes to identify their loved ones, and with these two new identifications, we continue to fulfill that sacred obligation,” Dr. Barbara A. Sampson, Chief Medical Examiner of the City of New York, said in a release.

“No matter how much time passes since September 11, 2001, we will never forget, and we pledge to use all the tools at our disposal to make sure all those who were lost can be reunited with their families.”

The efforts to identify victims of the World Trade Center attack is the largest and most complex forensic investigation in the history of the U.S., according to the OCME.

Morgan’s DNA was confirmed from remains found in 2001, while the unnamed man was confirmed through DNA found in 2001, 2002, and 2006. Family members were able to send in DNA samples in an effort to match the findings.

There have been around 22,000 body parts recovered for the OCME to test, the New York Times reported.

A large sum of victims has still not been identified, as 1,106 people out of the 2,753 death toll from the World Trade Center attack are still left as unknown.

“We continue to push the science out of necessity to make more identifications,” Mark Desire, assistant director of the OCME Department of Forensic Biology and manager of the World Trade Center DNA Identification Team, said in the release.

“The commitment today is as strong as it was in 2001.”