Making Unique Observations in a Very Cluttered World

Thursday, 15 January 2015

New DNA technique may reveal face of killer in unsolved double-murder -

New DNA technique may reveal face of killer in unsolved double-murder - 

There were no witnesses to the gruesome murder of a South Carolina mother and her 3-year-old daughter inside a busy apartment complex four years ago. But a new technology that can create an image of someone using DNA samples left at crime scenes might bring police closer to catching the killer.

Reston, Va.-based Parabon Nanolabs, with funding from the Department of Defense, has debuted a breakthrough type of analysis called DNA phenotyping which the company says can predict a person's physical appearance from the tiniest DNA samples, like a speck of blood or strand of hair.

The DNA phenotyping service, commercially known as "Snapshot," could put a face on millions of unsolved cases, including international ones, and generate investigative leads when the trail has gone cold.

"This is particularly useful when there are no witnesses, no hits in the DNA database and nothing to go on," Dr. Ellen McRae Greytak, Parabon's director of bioinformatics, told FoxNews.com.

"This is particularly useful when there are no witnesses, no hits in the DNA database and nothing to go on."
- Dr. Ellen McRae Greytak, Parabon Nanolabs

"Traditional forensic analysis treats DNA as a fingerprint, whereas Snapshot treats it as a blueprint -- a genetic description of a person from which physical appearance can be inferred," Greytak said.

Parabon's new technology reads the parts of the human genome that code for the differences in physical appearance between people. Snapshot is able to predict such critical traits as skin color, hair color, eye color and face shape. It can also predict the individual's ancestry as well as highly-detailed traits, like freckles.

Using sophisticated computer algorithms that have been trained on thousands of reference samples, Snapshot translates this raw genetic code into predictions of physical traits. These are then combined to create a composite profile, or "digital mugshot" of an unknown suspect -- with remarkable accuracy, according to the company.

"Traits are generally predicted with more than 80 percent confidence, and importantly, Snapshot also reports which phenotypes can be excluded with more than 95 percent confidence," said Greytak.

While developing the technology, the company "made thousands of predictions on people who we knew" to ensure accuracy, she said. 

The investigator or crime lab sends evidence or extracted DNA to a Snapshot partner lab, where the DNA is run on a genotyping machine to produce the genetic information, according to the company. This genetic information is then securely transferred to Parabon, where an analyst runs it through Snapshot's predictive models to produce a prediction. A report of the results is then delivered to the agency that requested it.

The new DNA analysis, however, is not able to predict age and height -- traits Greytak described as "very complex."

For investigators in Columbia, S.C., a digital mugshot created by the company might provide a break in a 4-year-old double homicide that remains unsolved.

The bodies of 25-year-old Candra Alston and her 3-year-old daughter Malaysia Boykin were found inside their home at the Brook Pines Apartments in Columbia on Jan. 9, 2011. There were no signs of forced entry, leading police to believe Alston and her daughter knew the killer or killers.

Police have not disclosed how the mother and child died, only saying Alston and her daughter were killed by different means. A laptop, Gucci purse and trash can were stolen from the apartment, as well as gifts the 3-year-old had received for Christmas.

The one clue detectives had was an unspecified DNA sample left at the crime scene.   

Throughout the course of the investigation, police interviewed close to 200 people, 150 of whom submitted their DNA to authorities. But none of the samples proved to be a match, according to Mark Vinson, a cold case investigator with the Columbia, S.C., Police Department.

The police department then turned to Parabon's DNA phenotyping to create a facial image based on DNA left at the crime scene. Vinson said the computer-generated photo is a "person of interest" in the murders.

"This is DNA from just one person and it’s possible more than one person was involved," Vinson told FoxNews.com. The person of interest is dark-skinned with brown hair and brown eyes. The picture does not indicate an exact age, so the individual could be older than he appears.

Parabon tested their predictions against known photographs, such as this one.
"We suspect the child also knew the person who did this, which might explain why she was killed," Vinson noted.

"We're very hopeful this composite

could be the thing that prompts someone to come forward," he said.

While several agencies are now using Snapshot to help solve cold cases, including international ones, the Columbia, S.C. Police Department is first in the nation to publicly release a digital image generated by the new DNA analysis.

Anyone with information on the murders of Alston and her daughter is urged to contact CRIMESTOPPERS at 888-CRIME-SC or log onto www.midlandscrimestoppers.com.

Read more -

Daily walk adds years to your life: Just 20 minutes a day is enough -

Daily walk adds years to your life: Just 20 minutes a day is enough - 

A BRISK daily 20-minute walk could reduce the risk of an early death by almost a third, a new study shows.

Lack of exercise is responsible for twice as many deaths as obesity, it says. Couch potatoes face greater danger from deadly cardiovascular problems like heart attacks and stroke as well as some cancers.

However, a 20-minute walk at a vigorous pace, or a cycle ride of the same duration, would move an individual from being classed as inactive to moderately inactive.

That small change alone would reduce their risk of early death by between 16 and 30 per cent, the Cambridge University researchers found.

Across the entire UK population, exercise from a young age would lead to an increase of nearly 12 months in average life expectancy. Individuals moving from total inactivity could gain many more extra years. 

Even a small increase in physical activity each day like walking up escalators or using the stairs instead of the lift could provide significant health benefits.

Exercise for 20 minutes is recommended as a minimum and, where at all possible, more extended exercise should be carried out to achieve even greater benefits, the study says.

Professor Ulf Ekelund, head of the research team, said: “This is a simple message – just a small amount of physical activity each day could have substantial health benefits. Physical activity should be an important part of our daily life.”

The researchers from Cambridge’s Medical Research Council Epidemiology Unit used the most recent available data to study 9.2 million deaths among European men and women. 

Their report, published yesterday in the American Journal of Clinical Nutrition, estimated that 337,000 deaths were caused by obesity but more than double that number, 676,000, could be attributed to physical inactivity.

Research team member Professor Nick Wareham said: “Whilst we should continue to aim at reducing population levels of obesity, public health interventions that encourage people to make small but achievable changes in physical activity can have significant health benefits and may be easier to achieve and maintain.”

He said the biggest killers are cardiovascular disease and types of cancer like cancer of the intestines which exercise can ward off.

“Brisk walking is just an example, as doing any exercise for the required time is just as good,” he said. 

“The brisk walk is just a little bit quicker than normal, rather than window shopping. Even doing things like using the stairs will help.

“We used brisk walking as most people can do it and have a good relationship with it. 

"Adults should aim to do at least 150 minutes of moderate intensity activity a week, carrying it out in sessions of 10 minutes or more.”

The findings are believed to be particularly important because of the scale and length of time carried out on follow-up analysis.

To measure the link between physical inactivity and premature death, researchers looked at data from 334,161 men and women across Europe, with just under a quarter of participants categorised as inactive.

Over a 12-year period it was found that the greatest reduction in risk of premature death came when people moved from the inactive and moderately inactive group into activity.

June Davison of the British Heart Foundation, said: “The results of this study are a clear reminder that being regularly physically active can reduce the risk of dying from coronary heart disease.”

The findings back up those from another recent study in which researchers at Cardiff University School of Medicine concluded that regular exercise, sensible eating, maintaining a healthy weight, minimal alcohol consumption and no smoking were the simple steps that guarantee longevity.

Read more -