Innocent but Dead

Forensic science has once again disproved facts about the past that were assumed to be true. Cameron Todd Willingham was sentenced to death in the state of Texas for the murder of his children by means of arson, but forensic evidence has recently proven that he was completely innocent. The fire broke out on the night of December 23rd, 1991. Cameron and his children were at home, and since his family was poor, his wife went out to get the children presents from Salvation Army. The fire, now proven to be completely accidental, broke out and he awoke to the sound of his screaming children. He tried to save them but was pushed back by the intense smoke and fire. Willingham, who was later convicted of capital murder, had to be restrained and handcuffed as he continued to try to get into their room. During testimony, the prosecution convicted him of killing his children on the basis that “they were getting in the way of his drinking and dart playing”, even though there was no real evidence to go by. Only until a few weeks before his death, however, did evidence show that there was no sign of arson. Craig Bayler, a forensic scientist who was hired by private commission, said that the fire marshall who testified on Willingham’s case “seems to be wholly without any realistic understanding of fires”. Forensic scientists who examined the case recently systematically knocked down every indication that the fire was caused by arson. Unfortunately, it was too late for Mr. Willingham.


-Luke Nichols
http://www.nytimes.com/2009/09/01/opinion/01herbert.html?_r=1

DNA Evidence Can Be Fabricated, Scientists Show

DNA Evidence Can Be Fabricated, Scientists ShowCLO

By ANDREW POLLACK

Published: August 17, 2009

Scientists in Israel have demonstrated that it is possible to fabricateDNA evidence, undermining the credibility of what has been considered the gold standard of proof in criminal cases.

The scientists fabricated blood and saliva samples containing DNA from a person other than the donor of the blood and saliva. They also showed that if they had access to a DNA profile in a database, they could construct a sample of DNA to match that profile without obtaining any tissue from that person.

“You can just engineer a crime scene,” said Dan Frumkin, lead author of the paper, which has been published online by the journal Forensic Science International: Genetics. “Any biology undergraduate could perform this.”

Dr. Frumkin is a founder of Nucleix, a company based in Tel Aviv that has developed a test to distinguish real DNA samples from fake ones that it hopes to sell to forensicslaboratories.

The planting of fabricated DNA evidence at a crime scene is only one implication of the findings. A potential invasion of personal privacy is another.

Using some of the same techniques, it may be possible to scavenge anyone’s DNA from a discarded drinking cup or cigarette butt and turn it into a saliva sample that could be submitted to a genetic testing company that measures ancestry or the risk of getting various diseases. Celebrities might have to fear “genetic paparazzi,” said Gail H. Javitt of the Genetics and Public Policy Center at Johns Hopkins University.

Tania Simoncelli, science adviser to the American Civil Liberties Union, said the findings were worrisome.

“DNA is a lot easier to plant at a crime scene than fingerprints,” she said. “We’re creating a criminal justice system that is increasingly relying on this technology.”

John M. Butler, leader of the human identity testing project at the National Institute of Standards and Technology, said he was “impressed at how well they were able to fabricate the fake DNA profiles.” However, he added, “I think your average criminal wouldn’t be able to do something like that.”

The scientists fabricated DNA samples two ways. One required a real, if tiny, DNA sample, perhaps from a strand of hair or drinking cup. They amplified the tiny sample into a large quantity of DNA using a standard technique called whole genome amplification.

Of course, a drinking cup or piece of hair might itself be left at a crime scene to frame someone, but blood or saliva may be more believable.

The authors of the paper took blood from a woman and centrifuged it to remove the white cells, which contain DNA. To the remaining red cells they added DNA that had been amplified from a man’s hair.

Since red cells do not contain DNA, all of the genetic material in the blood sample was from the man. The authors sent it to a leading American forensics laboratory, which analyzed it as if it were a normal sample of a man’s blood.

The other technique relied on DNA profiles, stored in law enforcement databases as a series of numbers and letters corresponding to variations at 13 spots in a person’s genome.

From a pooled sample of many people’s DNA, the scientists cloned tiny DNA snippets representing the common variants at each spot, creating a library of such snippets. To prepare a DNA sample matching any profile, they just mixed the proper snippets together. They said that a library of 425 different DNA snippets would be enough to cover every conceivable profile.

Nucleix’s test to tell if a sample has been fabricated relies on the fact that amplified DNA — which would be used in either deception — is not methylated, meaning it lacks certain molecules that are attached to the DNA at specific points, usually to inactivate genes.

Infra-red helps find hidden tattoo

There is a new use for infra-red cameras that can help Forensic Scientists solve crimes. Forensic scientists look at tattoos as a way of identifying suspects in investigations, but criminals can easily have them changed or updated. Scientist at the University of Derby in England say that they can use infra-red cameras to determine if tattoos are originals or if they have been altered. Using a digital camera sensitive to infra-red, researchers can see if there are hidden layers or changes to the original tattoo deeper in the skin. In an experiment researchers were able to see that a student who had a tattoo of a butterfly on his back was actually covering up an original tattoo of an imp. With this new infra-red technology scientist will be able to find determine if there suspects were able to alter there tattoos to possibly get away with the crimes the committed.

http://www.google.com/hostednews/ukpress/article/ALeqM5i00xsIi0OoXaL3y9lTo3LLfic_Iw

Scent Dogs to ID Perpetrators

Matt McCarthy
December 13, 2009
Forensics
Dogs

This article discusses the controversial method of using trained dogs in “scent line ups” to link a suspect to a crime scene. This method has come under scrutiny because of the potential for cross-contamination of scents and the dog’s perception of a human’s attention to the container that holds their scent. Most of the FBI is against this method and says dogs should only be used to find a crime scene or suspect by using scents but shouldn’t be able to pick one out of a line up. However, Thomas Litner is a FBI agent who claims this practice is useful and has been around for a long time. This method is widely used in Texas where people are currently starting lawsuits against local sheriff departments for being sentenced because of a dog scent line up.

http://thelede.blogs.nytimes.com/2009/11/04/dogs-forensic-science-and-scent-lineups/?scp=3&sq=forensic%20science&st=cse

Crime Scene Imperfections

This article on “crime scene imperfections” was very educational and also very unsettling. This article talks about how crime investigation shows are sometimes far from the truth. The National Academy of Sciences has observed these shows and has found “various continuity errors” from the show to actual government proceedings. In addition to that, the National Academy of Sciences also discovered that the field of forensic science is “grossly deficient.”

One of the reasons for this is because many forensic labs are poorly funded and staffed with scientists who are poorly trained. The N.A.S. also said that the problem with forensic science is that there is little evidence of the accuracy and reliability of most forensic methods. Especially ones that rely on expert interpretation.

Some techniques such as “Nuclear DNA analysis” only have a miniscule likelihood of error, whereas, many other well known methods have no proof that they work consistently. Methods such as those that can identify a guilty person or link a weapon to a crime scene are those that are being called into question. It is believed that these processes can help focus an investigation but can not always provide infallible evidence of guilt. Even in fingerprint analysis, it is said that the final ruling can be biased because of an examiners knowledge of the case. These Examiners have sometimes disagreed wit their own past conclusions when viewing the prints in a different context.

In the end, the N.A.S. makes many suggestions for the improvement of forensic science but there appears to be a lot of work before it becomes a highly-respected field of science.

http://www.nytimes.com/2009/02/21/opinion/21sat2.html

'Smell Of Death' Research Could Help Recover Bodies In Disasters And Solve Crimes

http://www.sciencedaily.com/releases/2009/08/090816211837.htm

In this article, it focuses on a device that can help determine the time elapsed since death of victims in natural disasters. Currently the “gold standard” in this type of recovery is a specially trained kind of dog. While they are able to locate bodies in disasters such as hurricanes, tornadoes, and earthquakes, it takes a lot of money and manpower to train them and the time since death cannot be determined. The way these dogs can find the body is the scent of at least one of thirty compounds a body releases during its death. For a more cost effective method, as well as more knowledgeable discoveries, scientists are working on a device that would work by detecting one of these thirty compounds. Not only would it be able to locate the source, but also with its ability to identify the compound in the air, they process of determining the time of death would be much more accessible. 

New Contested signs of mass cannibalism

Scientists at the University of Bordeaux 1 in France have recently discovered remains of mass cannibalism at the remains of a village now known as Herxheim. Though they say that it is difficult to confirm if there were any ritual sacrifices revolving around these deaths, but they confirm from the skeletal markings that these human beings were "butchered like animals" with markings indicated that the flesh was stripped from the bone.

Such an account is extraordinary because it represents a rare example of cannibalism amongst Neolithic humans. Previous to this finding, the only such case only existed in a French cave where six 6,000 year old skeletons were found butchered and buried alongside with the skeletons of animals.

Some evidence reported on the skeletons include incisions from primitive tools, primarily to accomplish gruesome tasks like separating the ribs from the spine. heads were also skinned, and muscles removed from the brain to best extract the skullcap. Incisions and scrapes on jaw bones indicate that tongues were also cut out. Similar markings on bones indicate the marrow being removed.

Though these pieces of evidence only support this hypothesis and don't prove it indirectly, scientists are still studying these remains.

Vitreous Humor in the Eye Helps to Establish Time of Death

http://www.sciencedaily.com/releases/2008/12/081204133857.htm

Forensic researchers from the University of Santiago have made a discovery on a new way to calculate the time of death. Although livor mortis, rigor mortis, and algor mortis are three of the known ways in which forensic scientists calculate the time of death, this new discovery can help find the time of death with an easier technique. By observing the vitreous humour, located in the eye of a dead body, scientists can predict the approximate time of death in humans. Software is being developed to make it possible to get even more specific dates, called post mortem intervals (PMI). Conclusions made from this information will help police and others involved in a crime scene come to more accurate verdicts. José Ignacio Munoz Barús, one of the authors of the study, says that the math models created to make said software easier to use are “more flexible, useful and efficient”. He also adds that previous methods, such as deterioration of DNA or biochemistry of the citreous humour, were not as effective as the ones that science research has recently provided them with. Research has proved that models such as GAM (generalized additive models) are SVM (support vector machines) are much more useful. The researchers have stated that since the 19th century and the start of forensic studies, the exact time of death has been one of the milestones in which researchers have been trying to make, and with this new method many contributions are made into reaching this goal.

Link for the Brain Article

http://www.nytimes.com/2009/12/03/health/research/03brain.html?_r=1&ref=science

Dissection Begins on Famous Brain

This article is talking about a scientific phenomenon regarding a case from 1953. Henry Molaison needed brain surgery, where his doctor removed two slug-sized chunks of brain tissue to try and prevent Molaison from continuing to suffer from seizures, which he would suffer from frequently at the young age of 26. However, the procedure was botched by the doctor performing the operation, resulting in Molaison being left completely unable to form new memories. Following Molaison's death last year at the age of 82, scientists have recently begun dissecting his brain to try and learn more about this remarkable case. During this dissection, over 2500 samples of brain tissue will be collected, all of which will be placed in a computer recording system. This will produce a "Google Earth-like map" of Mr. Molaison's brain. Scientists are hoping that this extensive study of the brain will provide a better understanding behind how memories are formed by the brain, as well as examining what happened to Mr. Molaison to cause his sudden inability to form memories.