Who Killed Tair Rada?

Zdorov’s investigation and the search of his belongings resulted in findings indicating behaviors that increase the likelihood of his guilt: he kept a knife collection, read an article on how to neutralize an enemy with a knife, and claimed to have thrown away the pants he was wearing the day of the murder. 

Yet, just as a bigger fishing net catching more fish is not indicative of more fish in the area, the wider and more thorough the search and investigation, the less weight should be attributed to each piece of evidence arising from it. Thus, as Zdorov’s physical and digital life was combed through, we would actually expect to see evidence of similar level, even from someone innocent. As such, Zdorov’s behavior as a whole only slightly raises the likelihood of his guilt.

Although some minor claims of strange behavior or lying have been made against them, Tair’s schoolmates did not exhibit any unexpected behaviors after Tair’s murder. Moreover, despite 10 or more students being interrogated, no confessions were made nor were any substantially incriminating statements or evidence given to the interrogators. Neither were such statements made in the years since the murder. Studies, and our own analysis of teen murderers, found children to be likely to confess under investigation, as well as spontaneously confess to friends. The lack of confessions or suspicious activity by the schoolmates, significantly reduces the likelihood for their hypothesis. 

After Zdorov’s arrest, he was interrogated intensively by police investigators, and a Russian-speaking undercover informant, Arthur, was planted in his prison cell with the promise of financial rewards if he could elicit a confession from Zdorov.

Zdorov eventually confessed and reenacted the murder on 19th December 2006. A day later, he recanted his confession, claiming that he was under extreme pressure and that the argument between him and Tair that he claimed led to him murdering her never occurred. The weakness of his confession and his overall pattern of behavior are consistent with a false confession given in order to obtain a lighter sentence, which reduces the likelihood of his guilt. 

Zdorov’s confession has elements that may be claimed to make it more genuine, and others that make it less so. We therefore used general statistics of false confessions, which resulted in a substantial increase of the Zdorov hypothesis.

Adir Habani, Ola’s ex-boyfriend, testified to the police in 2012 that Ola had confessed to him about murdering Tair the day the murder was committed. He recounted Ola’s story of how she entered the school as well as showing him the bag in which she kept her blood-stained clothes and knife. The police dismissed this at the time as the ramblings of a vengeful ex. However, the testimony’s high level of accuracy, the rarity of false accusations of a confession, and two further claims of Ola confessing, increase the likelihood that Adir’s testimony is true. Overall, this substantially increases the likelihood of the Ola hypothesis. 

A peace symbol was carved onto the door of the toilet stall in which Tair was murdered. The symbol has been found in Ola’s jewelry and art around the time of the murder, slightly increasing the likelihood that Ola is the murderer.

No forensic evidence was found that linked Zdorov to Tair’s body or to the crime scene. Similarly, none of Tair’s DNA was found on Zdorov’s belongings, despite the extraordinary effort to find her DNA. As such, this reduces the likelihood of the Zdorov hypothesis.

The crime scene similarly did not include forensic evidence of Ola (other than Adir’s hair which is purposefully ignored). However, since she is claimed to have come prepared, and was not thoroughly investigated, the Ola hypothesis is reduced by a smaller factor.