WAUSAU, Wis. (WSAU) - Two FBI analysts testified Monday that a hair found on the waistband of the sweatshirt accused killer Raul Ponce-Rocha wore the day of Breanna Schneller's murder was one that she naturally shed.
Trace evidence examiner Josh Friedman said the hair found on the sweatshirt was different in length and color than Schneller's. But DNA examiner Leslie McCurdy said that the hair's DNA matched Schneller's DNA.
"Schneller cannot be excluded as a potential source for that [waistband] hair," McCurdy said, adding that it is possible that Schneller is not the source based on maternal inheritance.
McCurdy gave jurors a crash course in biology, describing DNA as the genetic code that makes up who we are. There are two types of DNA – nuclear, which can positively identify someone as the source of evidence like hair, and mitochondrial, which comes from the mother and can help identify someone as a possible source. McCurdy only studied the hair’s mitochondrial DNA because hairs have little nuclear DNA that can be examined.
Still, the analysts' testimony was key to the prosecution's case because it directly links Ponce-Rocha to Schneller's death.
Schneller's fiance, Sebastian Ramirez, testified last week that Ponce-Rocha visited the apartment he and Schneller shared twice before the murder but never had any physical contact with her.