but on this day, she never arrived. co-workers called helena s husband at work. he immediately drove home and found the front gate locked. when he peered over the fence, he saw his wife s body. roger was in total shock. and he first called gen-probe. he didn t call the police. he called gen-probe. that shows how disoriented he was. the crime scene appeared to be staged. it had the earmarks of a robbery, but no money was missing from helena s wallet. you had her purse that was strewn about. they preserved all of that for fingerprints or other evidence, of which, unfortunately, there were none. there was no physical evidence left. obviously, he wore gloves. i mean, one safely can assume
roger was out of town on a business trip. in the middle of the night, a man suddenly appeared in helena s bedroom and threatened to kill her. helena was sexually assaulted, then robbed before the assailant made his getaway. dr. greenwood described her assailant as being fairly tall, slender, athletic, with a complexion, perhaps, of part half black or a hispanic person, an olive complexion. she couldn t see his face because he had a hooded sweatshirt pulled up so that only his eyes showed. the assailant entered the home through a kitchen window. but it was helena s friend who found a key piece of evidence that police had overlooked. outside on the deck near the kitchen window was a teapot from
you start with one after one round of pcr, you end up with two, then four, then eight and so on. the big advantage of pcr for forensic work is that it is so sensitive. very small amount of dna can yield a very large amount of information. it s a fortunate thing that they didn t try to test it at the time, because as you test biological material it s destroyed. had they, at the time of helena s autopsy, tested that material, they would have found nothing and the material would have been destroyed. when the biological material from helena s fingernails was tested using pcr, scientists made an important finding. on some of the fingernail clippings, they found only dna that was consistent with dr. greenwood s. and on one of the clippings, they found dna that was essentially pure, not from dr.
they knew who killed helena greenwood and they knew it was david paul frediani, but they couldn t prove it. eventually helena greenwood s murder was relegated to san diego s cold case files and forgotten. over the next several years, helena s parents died, her husband, roger, developed cancer and he, too, passed away. and who is there to mourn for helena? very few and growing fewer. and gen-probe went about the work helena had been pursuing before her death, looking for ways to use new dna technology for quicker, faster medical diagnoses. david frediani served only three years of his five-year sentence and was released.
brilliant, quiet, honest and a hard worker. she earned a ph.d. in microbiology and was an executive in the biotech industry. she was not only an excellent scientist but she had marketing skills. and those two things often are not concurrent. helena was very forward thinking, especially looking at technology. but she also knew the power that technology by itself doesn t market a product. basically it s the human need. if there s a human need, there s a product. that s required. helena and her husband, roger, a landscape designer, lived in atherton, a quiet suburb outside san francisco. our story begins on a saturday night in april of 1984 when