The murder of a 13-year-old schoolgirl Tair Rada in 2006 could yet be reopened based on new evidence, though its value is still being weighed. While the lawyers defending the convicted murderer argue that the new evidence, analysis of mitochondrial DNA from hairs found at the murder scene, is valuable, officialdom is still divided.
Just how reliable is mitochondrial DNA evidence, especially if the issue at stake is a murder case? In some cases, this genetic information can lead to identifications, says Dr. Bublil, head of the DNA lab at Israel's Institute of Forensic Medicine. Before using it as evidence in court, it bears knowing the limitations of analyzing mitochondrial DNA, she says — but saying that it is valueless is excessive. At the time, Israeli authorities sent some of the hairs to the United States for analysis: "If the test has no value, why were the hairs sent to the U.S. in the first place?" Bublil presses.
The hairs in question were found at the crime scene where Rada was murdered in her school in 2006. Bublil conducted the first analysis of the hairs, which were sent in 2007 to the U.S. for further testing.
A man named Roman Zadorov was found guilty, in September 2010, of murdering Rada, but the hairs match the DNA of a man known as A.H.
The argument over the merit of the hairs was between state prosecutors and the lawyer defending Zadorov, who say the hairs bolster A.H.'s version of events: that his previous girlfriend, A.K., had confessed to him that she had murdered Rada while wearing his clothes. That story is congruent with the new forensic evidence.
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Mitochondria are organelles within our cells that actually have DNA of their own. The nuclear cell DNA derives half from mother and half from father; the mitochondrial DNA is inherited from mother, period.
Testing mitochondrial DNA iattests to matrilineal family relations, and crucially, can sometimes be performed on hairs with no roots. Testing nuclear DNA produces results that are far more accurate: but in the case of hair, it can't be done without the roots (which have cells; hair doesn't).
Sometimes, under some circumstances, rootless hairs can be tested for the much smaller strands of mitochondrial DNA.
Haaretz has learned that of the 76 hairs found at the scene, only 20 were sent for testing and nine were sent onwards to the U.S. labs, for mitochondrial DNA testing, which was not available in Isael in 2006.
Of the 20 hairs, five underwent mitochondrial DNA testing. Of the five hairs that were tested, the results of three were ambiguous. Now these are have been retested, last week, at the Forensic Institute, at the behest of Zadorov’s attorney Yarom Halevy.
The prosecution had objected, claiming that the tests had limited value as evidence, even though a comparison with Zadorov was done in 2007, showing no match. Ultimately, at the instruction of the Supreme Court, they attorneys consented to the tests, which were paid for by Zadorov.
“The profile we got from A.H. was exactly the same as on the hairs found at the scene,” Bublil told Haaretz. But all the final report says, is that he cannot be ruled out, nor can anyone matrilinerally related to him — his mother, sister, brother or cousin on the mother’s side, if there are such.
"When we checked the incidence of such a profile in the data bank we found that the specific profile from this hair, fitting A.H., appears zero times in 26,000 different international lines. This doesn’t mean zero people in the world have that profile and that this is the only one in existence. Even so, a discussion began asking how many people carry this profile or the same line. We can’t determine this. Eight million people [Israel’s population] is not the same as eight million lines,” she says.
On Friday, genetics expert Dr Doron Behar came to the Institute. Behar has constructed an Israeli database for his research. Bublil denies media reports implying that Behar said that the profile could fit tens of thousands of people. Behar would not talk with Haaretz until his report is complete, but Bublil says that Behar’s search did show A.H.'s profile to be an uncommon one, with an incidence of 0.45 percent.
"The absolute number of people fitting this profile is still unknown, but it’s not very common," Bublil says. "This means that 99.5 percent of the population is out of the question. That’s the significance of this evidence – we’re saying you can’t rule him [A.H.] out, whereas there are very many people you can.”
Meanwhile, back in 2007, the American lab identified two of the hairs as belonging to Rada herself.
Bublil finds that categorical statement surprising: there are other options — namely, Rada's own matrilineal line.
“The original American report says that one cannot rule out the victim or any relative on her maternal axis," she says. It's ostensibly logical that if she’s the victim and the hair matches her, then surely the hair should come from her. But it isn't necessarily so.
"The American report also has statistics showing that Tair’s mitochondrial DNA profile appeared 163 times in the international database. That compares with zero matches in the international database for A.H.'s profile. In other words, Tair's profile is very common.
"You could still question whether the hair was Tair’s. It could be 100,000 other people, but at the time, the finding was very convenient.
"No one claims that today. This is the most important point in the whole story. Why won't anybody state that it isn't her hair, that it could be from a lot of other people? Because in the circumstances and context of this evidence it’s reasonable that it’s hers, so no one imagines claiming otherwise. One can’t distort the rules of evidence one way when it’s convenient and another way when it’s inconvenient. The rules governing mitochondrial DNA don’t change.”
There are other tests one can perform on these hairs in order to make a more precise determination. “If the test tube with that hair’s DNA were found one could get better resolution on the question of whether it fits A.H., for one thing; other hairs never tested remain, too.
What about the hairs sent to the U.S. that were never tested? Superintendent Hanita Grant, who signed the police report, testified in court that she ordered the testing stopped after it turned out that Zadorov was the only suspect.
Grant had decided that since he worked at the school where Tair Rada was killed finding his hairs at the scene was of no significance. Also,, if they'd found hairs from an unknown person — they couldn't tell if it was somebody connected to the murder or not. Bublil says some of the untestd hairs are now in the possession of the
Bublil said that some of the hairs reached the Forensic Institute but they’re waiting for approval to conduct further tests. “We have no authority to decide on tests. All sides have to agree. As soon as they ask we’ll do the test” she added.
As to the appearance of another fight between prosecutors and the Institute, she said that the Institute found itself caught between the two sides of the legal argument. “Clearly there is a legal battle since there is a vacuum that people want to fill. But that’s not our business. Ultimately, we’re committed to the biological truth. Additional tests may aid the prosecution. They may help the defense. I don’t know and it’s not my concern. I think it should have been done and it’s good the test was performed."