The chain of evidence for the bloody swatch:
"1. Authenticity: The swatch was taken from the sofa where Hitler committed suicide in 1945 and was removed by U.S. Army Colonel Roswell P. Rosengren. The swatch was authenticated as human blood transferred from a gunshot wound.
The piece of material was in the soldier's possession until his death. Article from the Gettysburg Museum of History from 2021:
A Section Of The Couch That Adolf Hitler Killed Himself On Stained With Hitler’s Blood w/Photos
2. Forensic Analysis: Four rounds of DNA sequencing were conducted to compare the bloodstain's Y-chromosome with those from verified living relatives. The results confirmed the swatch's authenticity and matched the Y-chromosome to a male relative.
3. Historical Context: The swatch was part of a collection of wartime relics at the Gettysburg Museum of History. It was not archived or treated as a scientific sample until the museum began looking for original material linked to the bunker.
4. Scientific Interpretation: Geneticist Dr. Turi King led the interpretation of the DNA results, which identified genetic variants consistent with Kallmann syndrome and placed the sample in the top 1% of risk for traits linked to autism spectrum conditions, schizophrenia, bipolar disorder, and ADHD.
This chain of evidence provides a strong foundation for the historical findings presented in the documentary 'Hitler's DNA: Blueprint of a Dictator,' which has been widely discussed and analyzed."
The DNA from the blood on the swatch was determined to be Hitler's based on its comparison to the DNA of a known Hitler relative, which matched 100%. It couldn't possibly have been anyone else's blood but Hitler's on that couch specimen.