In 1985 , a biochemistry scientist was off at her home in southern California . It was a horrific crime that would go without prosecution for 14 days . That is , until the very research she had brought to her employer just before her expiry nail the murderer .
" Without advances in DNA , this slaying might have gone unprosecuted . It ’s been a long time come to justice,“The Guardianreports prosecutor Valerie Summers as having say .
Dr Helena Greenwood was a British - born scientist who moved to the United States with her married man in 1977 . A Sheffield University alumnus , she had discharge her doctor’s degree in biochemistry at the University of London and would go on to work in the research laboratories of Syva , a aesculapian diagnostics troupe , as the couple settled into their new home of Atherton , California .
In 1984 , their abode was targeted by David Frediani , a crimson man who worked as a financial analyst while also convey out burglary in wealthy neighborhood . Frediani broke into Greenwood ’s menage while she was alone and held her at gunpoint for several hours , during which time he sexually assaulted her before flee the scene . Greenwood reported her rape to the police and forensic samples were collected , but the investigation , led by Sergeant Stephen Chaput , was ineffective to pinpoint a suspect .
“Junk” DNA
After the attack , Greenwood was approached by Gen - Probe , a biotechnology company based in San Diego . It was a belittled start - up , but one that was leading the bearing in revolutionizing the role of DNA . They had been bring on a new way to name infective disease that used DNA instead of traditional cultures , and Greenwood was part of the team that would get such discovery out in the earth .
At this time , a crucial development was stretch in the labs of the University of Leicester , where geneticist Alex Jeffreys was enquire how “ junk ” DNA could be used to discover individuals ' genetic cloth .
“ Using the same basic techniques as Helena was helping to employ in the field of view of medical diagnostics , Jeffreys had found a fashion of memorialise the stutters as an decade - irradiation scene that bet alike to a supermarket barcode , ” explain Samantha Weinberg in her book , luff From The Grave : A True Story Of Murder And DNA . “ He believed that each ‘ barcode ’ might be unlike for every human . ”
“ Jeffreys applied for a patent for ‘ DNA fingerprinting ’ and published an article in Nature in March 1985 , detailing the results of his research . In San Diego , Helena understand it and border into a meeting of director of Gen - Probe , brandishing the diary : ‘ This DNA fingerprinting is going to be big , ’ she enjoin . ‘ I mean we should get into it . ’ ”
Fingerprints At The Scene
It was around then that a lead had come through for Chaput , a David Frediani who had been capture for indecent pic and was being inquire for several breach - Indiana . The probe requested fingerprint and turned up a match with one of those found in Greenwood ’s domicile .
The engineering science to definitivelyidentify an individual ’s DNAdidn’t yet be , but with enough to go on , a preliminary hearing was held and though Greenwood did n’t recognize her assailant , a trial engagement was set for September . However , despite the violent nature of the crimes he was accused of , Frediani was allow out on bail .
Greenwood never made it to the visitation . Shortly before her 36th natal day on August 22 , 1985 , her organic structure was found in the garden of the Del Mar home she had moved into with her husband . numberless forensic samples were have , but they did n’t line up anything that could colligate the offense to its most apparent suspect : David Frediani .
DNA Fingerprinting
Due to lack of evidence that could attach him to the murder , Frediani was condemn to just six years in prison and got let out after serving three – but that all changed in 1999 when Greenwood ’s murder was reopened along with300 other unsolved cases .
Led by San Diego County sheriff ’s homicide detectiveLaura Heilig , the project ’s end was to see if advancements in the same DNA skill Greenwood had upgrade in life could shine novel lighting on erstwhile crimes .
In 1985 , Alec Jeffrey’sDNA fingerprinting first started being usedin the courts , ab initio to reconcile immigration cases and later in the field of operation of forensics . It help secure the pursuance of Colin Pitchfork as the murderer of two teenagers , and identify old skeletal remains as likely being those of Josef Mengele , a Nazi doctor at Auschwitz .
The same technique was used to process a crucial small-arm of grounds that descend from Greenwood ’s fingernails , where enough genetical cloth was found to be tested . for sure enough , the desoxyribonucleic acid fingerprinting she had been so activated about served up Frediani on a plate 14 years after the execution .
accord to theSan Diego Union Tribune , a forensic scientist bear witness that there was a one - in-2.3 quadrillion chance that someone other than Frediani had left the genic fabric found under Greenwood ’s fingernails , and he was fleetly convicted of first - degree execution .
“ All these years , Helena pointed from her tomb at her manslayer , ” said Greenwood ’s co - worker , Gisela Koestner , “ because the evidence was under her fingernails . ”
