> Despite the substantial amount of blood on the walls and throughout the house, investigators found no biological evidence on Henning, Birch, or in the stolen car. To explain why, prosecutors relied on the testimony of Dr. Henry Lee, who at the time was the director of the Connecticut State Police Forensic Laboratory. Lee testified that although Carr had been brutally stabbed numerous times, including a cut to his jugular vein, the blood from his wounds had spattered in an "uninterrupted" fashion, meaning there was nothing between Carr's body and the wall. Asked whether the assailants would have had blood on their persons, Lee said, "My opinion is maybe."
> As part of his testimony, Lee used a crime-scene photograph of an upstairs bathroom that showed two towels by the sink. Lee testified that the towels had tested positive for the presence of blood.
...
> The towel and Lee's testimony about it took center stage. In 2008, the towel had been tested and no blood was found. In addition, there was no report indicating any previous test. Attorneys for Henning and Birch argued that Lee had testified falsely and that prosecutors had compounded that false testimony by using his misstatement in two separate closing arguments.
> As part of his testimony, Lee used a crime-scene photograph of an upstairs bathroom that showed two towels by the sink. Lee testified that the towels had tested positive for the presence of blood.
...
> The towel and Lee's testimony about it took center stage. In 2008, the towel had been tested and no blood was found. In addition, there was no report indicating any previous test. Attorneys for Henning and Birch argued that Lee had testified falsely and that prosecutors had compounded that false testimony by using his misstatement in two separate closing arguments.
https://exonerationregistry.org/cases/12854