How Yahya Sinwar was identified from a medical perspective - Explainer

The body of Hamas leader and chief terrorist Yahya Sinwar was discovered in the rubble of a building in Gaza. A glance at his dental structure was enough to suggest the body belonged to the notorious terrorist, but DNA testing was required for absolute certainty. So, what exactly is DNA, and how did the police carry out the test?

The end of the terrorist leader came through the identification of genetic material: Sinwar’s body was found among the ruins in Gaza, and photos of his remains clearly showed a dental structure matching his unique set of teeth, which included severe deformities like crookedness and gaps in both the upper and lower jaws. However, a definitive body identification typically relies on one method: comparing hereditary material, DNA.

Shortly after the body was found, parts of it—such as a single hair from his beard—were transferred to the forensic department of the Israel Police. Sinwar had been imprisoned for many years, meaning security forces had records of his fingerprints as well as his genetic material. With advanced technology, it is possible to identify genetic material months or even years after an event.

DNA is found in most of the cells in our bodies, located in the nucleus and mitochondria, the latter responsible for the cell’s energy. DNA, consisting of two strands, encodes our genetic information. Each strand contains sequences of nitrogenous bases, which pair with complementary ones on the opposite strand. Three pairs of bases form an amino acid, the building block of the body’s proteins.

When cells divide, DNA replicates itself exactly, preserving the genetic code. The wonder of DNA is its ability to remain intact for years, decades, and sometimes centuries, allowing forensic scientists to examine crime scenes long after events occur.

Identifying Sinwar

In Israel, DNA testing is conducted in two labs: the forensic identification lab of the Israel Police, which examines DNA from living people, and the forensic institute in Abu Kabir, part of the Health Ministry, which analyzes samples from deceased individuals.

Here’s how the meticulous process works: biological samples—such as bloodstains, hair, semen, skin cells, or saliva—are collected from the scene in sterile containers and sent to the lab.

Theoretically, any biological tissue can be tested, but the conditions in which the sample was found are critical. The drier the sample, the more accurate the results. Wet environments can degrade the sample due to bacteria and fungi, whose enzymes break down the DNA.

Next comes the demanding laboratory work: the samples undergo PCR testing, a process that amplifies DNA segments up to billions of times, allowing them to be compared with other genetic samples. Samples from the scene are compared with those taken from relatives. Samples from living individuals are collected via a cheek swab, which gathers cells containing hereditary material.

Since each person’s genetic material is a 50% combination from their mother and 50% from their father, a genetic profile can be created using 15 DNA regions, reflecting the parent’s combination. By comparing the genetic profile of the deceased with their parents, identification is possible. DNA comparisons can also be made with siblings, though this method is less accurate.

DNA analysis typically takes about eight hours, but with new methods, results can be obtained in as little as two hours. Indeed, the Israel Police confirmed Sinwar’s identity approximately three hours after the body was found.

Investigation methods are constantly evolving. One recent development involves testing DNA from the mitochondria, an organelle responsible for cell energy. Mitochondrial DNA is inherited solely from the mother and is more durable than nuclear DNA, allowing for the identification of individuals and missing persons even when there are no close relatives. Mitochondrial DNA can be compared with that of a grandmother, great-grandmother, and so on. With this technology, identification can even be made using degraded bone fragments.

Immediately after the body was identified, Maariv published the opinion of orthodontic experts who confirmed that Sinwar’s dental structure matched that in the photos of the body. According to these experts, there were several unique characteristics matching the jaw structure of both the body and Sinwar. Teeth are classified according to their unique numbers. According to the experts, tooth number 31 was significantly tilted, and there was a gap, known as a “diastema,” between teeth 31 and 32. A similar gap was found between teeth 11 and 21. Additionally, tooth number 21 displayed a characteristic fracture known as a “nutcracker” fracture. Moreover, tooth number 41 was higher than the bite plane.