Archive for the ‘DNA Detective’ Category

 

Italy wins ‘Hit of the Year’ Award

Wednesday, June 7th, 2017

Starting in 2017, a new international DNA database award was created and awarded by Gordon Thomas Honeywell Governmental Affairs (GTH-GA) to bring an increased awareness to the incredible power of forensic DNA databases to solve crime and provide closure to victims and their families and to also recognise the dedication of investigators and forensic scientists throughout the world.

This year’s inaugural “Hit of the Year” winner was Italy.

Our very own Vanessa was amongst this year’s panel of judges and we congratulate Italy on winning the award. 

ITALIAN MURDER CASE WINS THE 2017 DNA DATABASE HIT OF THE YEAR AWARD

New international award brings attention to the value of using criminal offender DNA database to solve crime and bring closure to victims and families

Vienna, Austria, May 17, 2017 — Gordon Thomas Honeywell Governmental Affairs (GTH-GA) has awarded the inaugural DNA Database Hit of the Year award to the Italian Carabinieri and Polizia di Stato for its dedicated work on the Yara Gambirasio murder case. The winning case was selected from 50 cases submitted by 15 countries, and was chosen by a panel of seven international judges with career backgrounds in forensic DNA. The award was announced during the annual Human Identification Solutions (HIDS) Conference held in Vienna, Austria.

“The DNA Hit of the Year Award is designed to bring increased awareness to the incredible power of forensic DNA databases to solve crime and provide closure to victims and their families. It also recognizes the dedication of investigators and forensic scientists throughout the world who use DNA databases to pursue justice,” said Tim Schellberg, GTH-GA’s President.

The judges selected the Italian case from five finalist cases. The four runner-up cases were from China, Austria, and two from the United States. A full list of submitted cases and a presentation describing this year’s award and case highlights can be found at www.dnaresource.com/hitoftheyearmain.html

Yara Gambirasio (of Brembate di Sopra, Italy) was murdered on November 26, 2010. To identify the suspect, whose full DNA profile was found at the crime scene, Italian authorities developed the world’s largest known DNA mass screen database. Using this tool, investigators and analysts embarked on a complex and exhaustive familial DNA searching scenario that ultimately led to an arrest on June 14, 2015. The suspect was convicted on July 1, 2016. “I have never seen a case where so much effort was put into finding a suspect through the use of DNA. The men and women of the Italian Carabinieri and the Polizia di Stato should be commended for their tireless work to identify the person that matched the DNA left at the crime scene,” said Rock Harmon, Retired Senior Deputy Prosecuting Attorney for Alameda County, California (USA), and one of the judges for the 2017 Gordon Thomas Honeywell Governmental Affairs Hit of the Year Award.

Media contact: Tim Schellberg – tims@gth-gov.com – +1 (253) 209-8818

About GTH-GA

Gordon Thomas Honeywell Governmental Affairs is globally recognized as experts in forensic DNA database policy, legislation, and law. For nearly twenty years, consultants at GTH-GA have consulted in over 50 countries and states on legislation and policies to establish or expand criminal offender DNA databases.

Sincerely,

Tim Schellberg

I Am Woman: Thank you!

Wednesday, September 21st, 2016

I have been inundated with messages of love and support since the showing of the below documentary on the work of the DNA Project.

It was not a journey I undertook alone and thank you to my amazing DNA Project family for your passion and unwavering support over the last decade.

In particular the documentary pays such beautiful tribute to my Dad, Johnny Lynch – it is the first time I have seen my Dad ‘live’ in video since his death (we didn’t realise my brother had these videos…) and it took my breath away — for my daughter and my family sitting around me, it felt as if he was in the room with us and you could have heard a pin drop as the tears fell upon our cheeks.

My Dad has always been my ‘silent’ partner in this journey, having not chosen to use his name in my work, because that was what my Dad was always about — he always told me that true charity is when you give something of yourself but never tell anyone about it — well in some ways that was what he did and in this programme it was his time to shine and I am so glad that his story was told, even though I know he would still be humble about it!

In loving memory of the true hero in this story, my dearest Dad, John Lynch

~ Vanessa

Thank you to Lisa Chait and Lauren Groenewald together with the whole “I AM WOMAN” team. It was a real honour for our DNA Project family to be part of your inspirational programme.

I AM WOMAN LEAP OF FAITH is a South African television and online series presented by storyteller Lisa Chait. It features the lives and Leaps of Faith of remarkable women exploring how they stepped into brand new territory when faced with life’s greatest challenges and opportunities. Each episode uncovers the turning points and pivotal moments of change in their lives. We also explore where they turned to when the chips were down.

To learn more about the series or to view past episodes, please visit www.iamwomanseries.com

Some of the wonderful comments we received via our social media and emails – Thank you all for your very kind words of support:

“Dear Vanessa, Congratulations…. what a lovely documentary. Your family have every reason to be so very proud of you. Both Brian and I thought that every interview was excellent and both felt very humbled to be connected to such a remarkable achievement and woman. I just wish that neither of us, (you and I) had to experience the trauma that we did for this to happen. You will be in the history books! Lots of love, respect, and admiration” ~ Diana Thomson (Mike Thomson Change A Life Trust)

“I hope you are all feeling very proud of what you did and achieved… I smiled, I laughed, I cried, I felt happy, I felt sad, but above all, I felt blessed and privileged to know you all. Vee, you really are the champion and all your seconds along the way have walked / run the race with you. I know that for you the hero in this story is and always will be Johnny – for me, it’s all of you. God bless – take care – lots of love” ~ Carol xx

“I just wanted to share with you how touched I was by your story that was aired last night. Thank you for touching the hearts of many others in a time of great sorry and pain. What a lady!!!!!!!!!!!! Thought I must share with you how much it meant to me” ~ Elsabe

“I watched a program of you last night,I am woman. What you have done is amazing and is a lasting legacy. May God bless you for your strength and courage. Thank you from a South African dad” ~ Rudi

“You’re an amazing woman Vanessa. When unsolved cases of someone dear to us go unsolved, it’s heart breaking. We salute you and thank you for your “Leap of Faith”” ~ Colleen

“I have cried while watching this very poignant story. What an incredible person you are Vanessa. I am amazed at your dedication and tenacity. You deserve more recognition for your brilliant work. Well done” ~ Alison

“Was so incredibly emotional and inspirational to watch last night. So much respect for what you and the team are doing for the country. Thank you” ~ Marieka

“Really heartfelt, whilst informative all at the same time” ~ Nolwazi

Change a Life – Mike Thomson murder feedback

Thursday, August 4th, 2016

We received the following incredible feedback from the Mike Thomson Change a Life Trust that we wish to share…

It was eight years ago that Mike Thomson was tragically murdered and the Mike Thomson Change a Life Trust was formed in his memory. In all these years his killers had not been brought to book but his mother, Diana, reports that the wait for justice is finally over.

On Tuesday, 26 July 2016, the final member and leader of the gang responsible for Mike’s murder was sentenced to 15 years for armed robbery and 20 years for murder. Although the sentence will run concurrently with the 37 years he is serving at present, it will add to the years he will not be eligible for parole. Diana says that, after all the years Razor Zulu has been completely unrepentant and has pleaded not guilty to the crime, he made an about face the day before the trial and plead guilty to the crime.  He also apologised to Diana and Lorna, Mike’s widow.

Two members of the gang had previously pleaded guilty and turned state witness against Razor Zulu and another man named Stofele. They were given 25 and 20 years respectively.  The final outcome has been that of the five members of the gang, three are in prison, one was killed during a gun battle after escaping from prison and Stofele was released for lack of evidence against him.

Mike’s family can finally take comfort that these people will not be at liberty to continue with their reign of terror for many years to come.

The DNA Project wishes to extend our heartfelt thanks to the Mike Thomson Change a Life Trust for their many years of amazing support.

Their continued support enabled us to bring about a positive change not only through our various projects and awareness campaigns, but most importantly in allowing us to champion the need for effective legislation in South Africa – which ultimately lead to the passing of the new ‘DNA Act’ – to make better use of forensic DNA evidence as a crime fighting tool.

Thank you!

9th Annual Women in Law Enforcement Conference

Monday, May 2nd, 2016

In the quest to discuss creative strategies in combating crime, ITC’s 9th Annual Leadership Development for Women in Law Enforcement conference (25 – 27 May 2016) will bring law enforcement entities together with the aim of strengthening collaboration and partnerships at all levels of enforcement, bringing together various enforcement directives in the quest to empower, inspire and awaken the spirit to leadership.

Both local and international speakers will boost exceptional individuals that have through their hard work and determination, put fellow women law enforcers on the global map and have proven that it is possible to lead, despite gender challenges.

The annual ITC conference also includes an awards ceremony on day two and is a platform where women law enforcers are recognised for their contribution to enforcement.

Some confirmed speakers include:

  • Major General Liziwe Ntshinga

Provincial Head: Directorate For Priority Crime Investigation (Hawks) Free State
SOUTH AFRICAN POLICE SERVICE

  • Annalene Marais

Deputy Chief of Police: Operations
CAPE TOWN METROPOLITAN  POLICE DEPARTMENT

  • Ursula Mc’Crystal

Head : Anti Money Laundering Surveillance
STANDARD BANK OF SOUTH AFRICA

  • Captain Elmarie Myburgh

Investigative Psychology Section: CR & CSM
SOUTH AFRICAN POLICE SERVICE

  • Lieutenant  Colonel Heila Niemand

Provincial Unit Commander Family Violence, Child Protection and Sexual Offence (FCS)
SOUTH AFRICAN POLICE SERVICE

INTERNATIONAL PERSPECTIVE:

  • Agent Valerie Parlave

Executive Assistant Director
FEDERAL BEREAU OF INVESTIGATION WASHINGTON

KEY STRATEGIES TO BE DISCUSSED:

  • Creating a culture of quality service delivery in law enforcement
  • Using various leadership traits as a woman in law enforcement
  • Looking at the role of law enforcement in addressing the protection of women and children
  • Advancing your management capacitation through stronger mentorship
  • Excelling as a woman law enforcer by utilising Emotional Intelligence to your benefit
  • Pursuing a career based on your passion to make a difference
  • Encouraging continuous education for women within law enforcement
  • Strengthening the fight against Cyber Crimes
  • Addressing physical and psychological challenges faced by women in policing
  • Women in law enforcement complementing instead of competing
  • Equipping yourself and your team with the right tools to execute your directive

To learn more about the conference please visit: http://www.intelligencetransferc.co.za/conferences/9th-annual-leadership-for-women-in-law-enforcement/

On the graveyard shift: this is what it’s like to collect South Africa’s dead

Friday, April 8th, 2016

Selby Cindi, from Johannesburg Forensic Pathology Services, and a Johannesburg metro police officer lift the body of an accident victim from a street in the Johannesburg CBD. Image: Alon Skuy

The following article published by the Sunday Times takes a fascinating look at South Africa’s Forensic Pathology Services.

Five nights, four bodies. Reporter Graeme Hosken and photographer Alon Skuy spent the graveyard shift with the men and women who collect South Africa’s dead.

Body #38 lies on a steel gurney in Carletonville Forensic Pathology Services’s “new” fridge.

The government-issued cream-coloured body bag refuses to seal, her arm hangs half out.

She’s just arrived. Half-naked, 14 stab wounds to the chest.

“Gogo” was found sprawled on the dusty ground in the backyard of her Bekkersdal home. Her bloodied white blouse ripped open, her skirt bunched around her waist.

She had been there for days. She lived alone.

“It’s tough,” says Sello Mabote, as he scrawls her “new ID” number on a beige toe tag.

“It’s especially tough when it comes to the families.”

For his colleague Mpho Marahoni it’s murders, the death of children, and surviving families that get to him.

“They are lost,” he says as he writes down the body’s details, “searching for answers, pleading for help.”

South Africa’s morgue officers have to be policemen, church ministers and counsellors to the families of the dead.

Body #38 is the 38th of 107 bodies collected by Carletonville’s mortuary officers so far this year.

To continue reading the full article, please click here.

SOURCE: This article was first published by the Sunday Times on the 30th of March 2015

How dead pigs can help nail killers

Monday, February 29th, 2016

A pig’s carcass lies in a cage at a secret ­location on the Cape Flats. Weather-monitoring equipment is attached to the cage. (Devin Finaughty)

It is surprisingly difficult to find a place in Cape Town to leave a 60kg pig to rot. It cannot be close to water, in a residential area or anywhere near agricultural land – there are certain biohazard requirements.

It also has to be secure, so that none of the accompanying R46 000-worth of weather-monitoring equipment is stolen.

“This has been the most difficult part of my project,” says Devin Finaughty, a PhD candidate at the University of Cape Town (UCT).

Finaughty is investigating how human bodies decompose in the Cape, and a pig’s body is the closest to an actual human body when the latter can’t be used. He is quick to point out that his project has undergone rigorous ethical clearance.

We are sitting at the Rhodes Memorial Tea Garden, and overhead the mercurial Cape weather cannot decide whether it wants to rain.

Behind us, an eavesdropping elderly couple is torn between curiosity and disgust as we talk about dead bodies washing up on beaches, the life cycle of maggots and the bloating of corpses in a vlei.

Belinda Speed, another UCT PhD candidate investigating human decomposition, stirs her tea and pulls her cardigan closer around her.

“When we get bodies [in forensic pathology laboratories] that are decomposing, the main questions are: Who is it and how long have they been dead?” she says.

This is what Speed and Finaughty have set out to investigate: Finaughty on land and Speed in the turbulent Cape seas.

Environmental factors

Bodies decompose differently, depending on the environment that they are in, and this information is necessary to determine a time of death and, if foul play is suspected, to find the person responsible.

“The decomposition process is extremely varied and there are various factors that influence how a body decomposes,” says Dr Jolandie Myburgh, a senior technical assistant and lecturer at the University of Pretoria’s Forensic Anthropology Research Centre.

These factors include the humidity of the region, and the types of insects and animal scavengers in the area, among others.

From our vantage point at the Rhodes Memorial, we have a panoramic view from the Cape Flats through to the Helderberg and Hottentots-Holland mountains. The landscape is vivid under the heavy grey clouds. In the distance, the Indian and Atlantic oceans crash into each other.

Right now, somewhere in that landscape, there are four dead pigs spread over 10 acres in “a secure, private location on the Cape Flats”. Their carcasses are lying inside galvanised steel cages and Finaughty goes out to the sites daily to weigh them.

Weight loss over time is an indicator of the rate of decomposition, and he uses this information, in conjunction with the weather data, to model how the bodies decompose.

This is particularly important for an area like the Cape, which is a unique biome with endemic animals and plants.

“Because of the mountain, Cape Town has seven biogeoclimatic zones, so a body found on Table Mountain will decompose at a different rate to one in a forested kloof or the Cape Flats,” he says.

Red romans

In False Bay, Speed’s pig is suspended in a stainless steel cage and a camera light flashes periodically in the murky water. She chuckles: “red romans seem to love flashing lights, so there are lots of photos of red romans.”

Unlike Finaughty’s cage, which is a metal mesh, Speed’s looks more like a 1.7m x 1.6m x 1m prison cell. She starts off explaining the cage with her hands, but soon takes out her cellphone to show me pictures of it and a photo of a red roman.

It is blurry in murky water. “Mine has large bars, so that sharks can’t take a bite of it [the pig].”

Known as “pig lady” and sometimes “Babe” by the research diving unit, Speed says: “Because of the different bays and coastlines, we’ve had cases where pieces of human bodies and bones wash up on the beach.”

Her research aims to fill in many of the blanks about what happens to human bodies after they drown or are thrown or fall into the seas ­surrounding the Cape.

The area is unique because of the meeting of the two oceans. This affects what happens to a body, from the temperature of the water, its oxygen levels and salt content to how deep it is and how far the body is from the shore.

Knowing the extent to which these factors determine body decomposition will help forensic services and the police determine how long the person has been in the water.

“I will be overjoyed if I can fit a pig into a wet suit,” Speed says. She laughs at my surprise. “That is the kind of cases we’re getting – and a wet suit preserves the body in an amazing way. Animals can’t get into the wet suit and small fish can’t chew through.”

Pivotal insects

These small animals – both on land and in water – are pivotal to the decomposition process.

Finaughty’s work focuses on the insects that drive putrefaction.

There are internal decomposers, principally the bacteria in the digestive gut, as well as external insects and scavengers.

“[We] often talk about how the climate influences the rate of decomposition, but climate does it indirectly … [for example in terms of] the timing of flies depositing new eggs and the amount of bacteria growth,” Finaughty says.

“Yes, you can pull out individual variables, but if you want to make inferences about the system as a whole, you need to look at the whole system.”

Finaughty and Speed’s research adds to the work that has already been done on human body decomposition in the Cape.

“Currently, we only have data on decomposition patterns in Gauteng and the Cape,” says the University of Pretoria’s Myburgh, whose master’s thesis was on postmortem intervals in South Africa.

There are many different climates and environments in South Africa. “Ideally,” she says, “we would like to have data from all the various regions in South Africa so we can compare the body found to local data, which will minimise the degree of error from using decomposition data from a region with a completely different type of environment.”

SOURCE: This article was first published by the Mail & Guardian on 19 February 2016.

Fingerprint brushes could transfer touch DNA, study says

Monday, February 15th, 2016

Locard’s Principle of Exchange has been an absolute fundamental in criminal forensics for a century. The concept that the perpetrator will always take traces of the victim and the scene with them, while leaving traces of themselves in exchange, is the basis of all modern investigation.

However, the principle has gotten a little more complex with how sensitive DNA tests have become in recent years. Secondary transfer of human DNA has been demonstrated through handshakes. Now, a study has found that fingerprint brushes used at crime scenes to find latent prints could actually be picking up and then dropping genetic material in different locations.

The DNA was found in low-copy number techniques, according to the Journal of Forensic Sciences study, authored by forensic scientists at Florida International University.

“The dusting of latent prints may dislodge cellular debris from the latent print or substrate. That debris then adheres to the brush,” they write. “This brush is then used on another item of evidence, or at another crime scene, where it is subject to the same mechanical maneuvering and where it can dislodge cellular debris, leaving traces of biological evidence not pertinent to the evidence being handled.”

The more-exacting polymerase chain reaction process of amplification led to detection of DNA transfer: in 5 of the 12 samples in the 28-cycle process, and a startling 10 of 12 tests using a post-PCR cleanup process.

But the risk of false associations based on the contaminated DNA was only “moderate,” considering their laboratory conditions and analytic procedures, they conclude.

Since the possibility exists, however, standard protocols to handling latent prints before DNA testing needs to be established to eliminate the possibility of false results.

“Under LCN conditions, it may be possible to obtain DNA results that are not relevant to the case due to a secondary transfer by fingerprint brush contamination,” they conclude. “Comparisons to these results may lead to matches or inclusions thereby potentially producing false associations between the evidence and crime scene.

“Improper procedures may lead to false exclusions or false association between evidence and crime scene,” they add.

Bruce McCord, the lead author of the study, and his team at Florida International University were the recipients of the most National Institute of Justice awards during 2015, totaling $1.5 million – partly for their DNA analysis work, and also for studies into forensic chemistry and other topics.

McCord told a university publication that he was working on a DNA analysis method for on-scene results within six minutes.

SOURCE: This article was first published online by Forensic Magazine on 12 February 2016 – http://www.forensicmag.com/articles/2016/02/fingerprint-brushes-could-transfer-touch-dna-study-says

4 Critical CSI Techniques Used in Terror Investigations

Wednesday, November 18th, 2015

The evening of November 13, 2015, may have begun as unremarkably as any other. By the early hours of the morning, however, a night of revelry had turned into an unconscionable tragedy — and the catastrophic loss of 129 lives.

Whilst a terrorist attack is designed to provoke panic through calculated chaos, the events that unfolded were unfortunately an echo of those that have occurred prior (and simultaneously) — by a common, real enemy.

These events engender a full-scale, comprehensive criminal investigation — especially in the event that there are suspects still at large, or insiders with prior knowledge.

Here, we recount the techniques — proven critical to gathering intelligence in the Paris attacks (November 2015) — that are used in the course of processing these scenes.

1. Severed fingers: DNA technology.

Rather remarkably, a severed finger recovered at the site of the Bataclan theatre — the seat of violence in this particular incident — led French authorities to identify the first of seven terrorists involved in the attacks.

So how does the process of identifying an attack from a mutilated body part work? Unlike a trace of bodily fluid recovered from a cleaner scene, a whole severed finger provides a copious amount of deoxyribonucleic acid, or the human body’s “blueprint” molecule. This is highly variable among a group of unrelated individuals.

The assigned technician would not, however, sequence the entirety of the genome isolated from the finger. This would be expensive, and an altogether wasteful endeavour.

DNA contains repeated sequences, with regions containing short, repeating units or STRs. For a variety of reasons — including lower mutation rates and their considerably smaller size — these shorter sequences are used to genetically differentiate people.

2. The smoking gun: ballistics testing.

The terrorists were armed with high-powered automatic weapons, thought to be Kalashnikov assault rifles. Military-class firearms, like these rifles, are prohibited across most of Europe — which raises the question: where did these individuals purchase these weapons?

The obvious answer is the black market (purchase from an illegal weapons broker) or smuggling the rifles in from abroad. Various countries in Europe have different customs regulations, which may have made it difficult to curtail the import of these weapons.

To determine precisely what firearm was fired that evening (assuming they are all the same type) — and perhaps trace the origin of this weapons to aid the investigation — ballistics analysts must examine everything from the bullet trajectory to shell casings.

Surprisingly, each type of military bullet also has a separate wound profile. By looking closely at the injuries sustained by the victims, examiners may be able to develop a more complete picture of what weapon was used.

3. Very loud noises: explosives.

The detonation of explosives outside the 80,000 capacity Stade de France was perhaps the first sign of impending danger. At this point we know that these attacks were well-coordinated: all of the suicide bombers wore nearly identical explosive devices.

The waistcoats and belts used an explosive called TATP, and contained identical batteries and push-button detonators. Triacetate tiperoxide can be produced cheaply, and using certain household ingredients.

Most likely, it took a highly-specialised and trained group of fire and explosive analysts to examine the chemical traces, or explosive residue, left behind in the debris. Samples from the surrounding areas would be tested using a variety of methods to determine precisely what compounds were utilised in the attacks.

4. Cell chatter: cybersecurity.

Digital forensics and cybersecurity — both to prevent attacks like these, and to ensure that digital infrastructure is protected — have come to the fore.

To start, an intelligence “tip-off” in this realm often begins with detection of higher “chatter” or the sheer volume of intercepted communications. However, there is evidence that the NSA has created a supercomputer (alongside its listening posts) that goes several steps farther: it looks for patterns and reveals codes in this chatter to make better sense of it.

In this case, officials in the US and Europe did pick up chatter in September about these attacks.

SOURCE: This article was first published by Forensic Outreach

DNA by the numbers

Thursday, November 5th, 2015

Nowadays increasing numbers of evidentiary traces are collected at crime scenes and submitted for DNA analysis at the forensic laboratories. However, almost 50% of the analyzed DNA samples do not result in valuable DNA typing information (1) and a few studies show that the possibility to actually obtain usable DNA profiles can depend on the trace type (2,3). Evaluating the DNA results obtained for various sampled traces can provide us information on which traces are most promising to select for DNA analysis. Such information can guide crime scene investigators in decision-making.

The study

Six European forensic laboratories1 from the EUROFRGEN network, gathered DNA yields from over 24,466 crime-related samples that were categorized based on biological source or sampled item.  The category ‘sample type’ includes various biological sources such as bodily fluids and tissues and the category ‘sampled item’ includes several items sampled for either saliva or contact traces.

DNA yield was used to predict the DNA profiling result.  Four categories were chosen based on in-house experience: 1) full profile, 2) usable partial or full profile, 3) partial profile possibly useful, and 4) no informative profile. Details on this categorization can be found in Table 1. These four categories inform us which are the most promising samples to select for DNA analysis.

Observations and conclusions

A total of 44 categories were made for the overall categories ‘sample type’ and ‘sampled item’. The number of samples in each category varies from 18 to 7104 and the results represent trends. In Figure 1 for each sample category, the percentages of samples with an expected type of profile are shown: dark and middle green bars indicate full and usable profiles; a light bar represents possibly useful profiles and a brown bar marks the category no profile. Within the overall categories, the sample categories are ranked from lowest to highest percentage no profile expected.

When comparing sample types, we see for instance that for blood samples in 93% of the cases a full profile and in 4% no profiles may be obtained. For feaces samples, on the other hand, the percentage no profile is much higher namely 24%. This variation is also observed when comparing various sampled items likely to carry saliva or contact traces: the percentage in the ‘no profile’ category is 2% for balaclavas and 29% for bottle lids and 0% for coat collars and 44% for plastic bags.

The proximity, intensity and duration of contact seem to contribute to profiling success as saliva items balaclava, cigarette end, chewing gum and toothbrush and contact items such as collars and headwear give high percentages of full profiles.

When regarding all categories, the five most promising samples to select are muscles, blood, coat collars, cigarette ends and balaclavas. On the other end of the spectrum, the five least promising samples are hairs, plastic bags, bullets, touch traces various and grip traces various. Importantly, for all categories full and usable profiles are obtained. For the sampled item bag plastic for instance 44% of the samples categorize into ‘no  profile’ while 43% may result in a full profile.

The category ‘partial profile possibly useful’ presents uncertainty as at least a partial profile is expected but it is difficult to predict whether DNA results will be usable for comparison studies. Aspects such as the number of contributors to a profile and mixture ratios will have a role here. Notwithstanding, this collaborative study gives insight in the DNA results of the several traces and may assist crime scene investigators in their decision-making in which many other aspects such as the context of an item in to crime are relevant too.

… To continue reading the full article by Anna A. Mapes, please click here.

SOURCE: This article was first published by Forensic Magazine on 20 October 2015.

What is a human chimera?

Wednesday, October 28th, 2015

Human chimera: What the rare condition is, and why there might be many more people with it than we realised.

This article was first published online by The Independent (UK) on 27 October 2015.

Doctors are finding more and more instances of human chimeras — a condition that might affect far more people than we realise.

Human chimerism hit the headlines this week after it was revealed that a man had failed a paternity test because he had the condition — which meant that the genetic father of his child was his unborn twin.

The condition occurs when one unborn child absorbs the cells of another miscarried sibling in the womb, leading to the surviving person taking some of the genes of their “ghost” twin. That can lead to strange results in the DNA of people that have the condition — but it can often go completely unnoticed.

The condition is relatively common in some animals — but it may happen more often than we realise in humans, and go unnoticed. And it may become yet more common, as more people use fertility treatments to conceive their children.

In previous cases, people have been found to have two different blood types, or to develop different sexual organs from those that would be associated with the rest of their body.

Another example involved Karen Keegan, a woman from Boston in the US who had a different set of genes in her blood cells and her ovaries. Her children were not genetically hers — and the real genetic mother was a twin sister that was never born.

In the case of the Washington man reported this week, different genes were found in his cheek — where the saliva in the test was taken from — and his sperm. That meant that he was excluded from a paternity test, but a DNA-based ancestry check showed that he was the child’s uncle.

But many people who have the condition will never take a paternity test for their children, or find out through other means. That is likely to mean that many people could have the condition, and never know.

Studies have suggested that the condition might be present in 21 per cent of triplets, and eight per cent of twins. But many of those people would never know — because testing is likely to show up the result, unless it is being searched for.

Chimerism might already be far more common than we realise, but it could become even more prevalent, Barry Starr, a geneticist at Stanford. Fertility treatments are much more likely to lead to multiple births, and so are in turn far more likely to produce more people with chimerism.

A version of the condition called “artificial chimerism” can also occur through transfused blood stem cells — though that is less common because transfused blood now tends to be hit with radiation to help the host absorb it — or through bone marrow transplantation.