Thursday, February 19, 2009
by blogger jgl
The Bring Your Own Slides session is often a highlight of the AAFS annual meeting. This year was no exception. The BYOS session is an opportunity for forensic scientists to share interesting stories from their work. There is always a mix of entertaining, light stories, along with more somber stories that are part of the profession (medical examiners are usually featured).
This session was hosted by Dr. Michael Baden of HBO's Autopsy. I think he usually hosts it. His talks are always good. Tonight he didn't have a feature, but threw in good comments throughout.
One of the top talks was by Sam Brothers, a computer forensics guy from US customs. He is a magician! I liked the card counting demonstration.
The feature of his talk focused on cell phone/GPS forensic work. iphones are unique for retaining voicemail in the phone... windows washer doesn't wash log files... a smashed (or chewed) sim card can still be analyzed... and your GPS knows where you are and where you've been. technology helps the good guys!
The always entertaining Mark Benecke (www.benecke.com) gave a "fun" talk on a german cannibal. He pointed out that cannibalism can be a tricky category when it comes to charging the crime. Homicide doesn't necessarily fit when a person volunteers to be killed and eaten by another person. Trust me, the details are even weirder than it sounds.
The real bones herself, Kathy Reichs stopped by and told a neat story about how research for one of her books helped lead to an answer in one of her cases. I'm not sure if i have the details right, but basically while researching a deceased Canadian who died in a Guatemalan civil war and a past leper community on Tracadie in New Brunswick, the local press (and possible accompanying documentary) led to someone coming forward admitting to raiding a graveyard when he was a 12-year-old kid. After a couple failed pranks, the bones were ditched in some woods. Years later, in 1989, the skull wound up in kathy reichs' hands and has remained unidentified. eh... i think i messed up the story... maybe it will be featured in an episode of bones.
other good talks as well. Did you know Dickens worked for a coroner? and wrote some articles for the Lancet?
by blogger jgl
Pictures later. I forgot the camera cable, although i noticed a radio shack on the 16th street mall.
I arrived at the American Academy of Forensic Sciences annual meeting (convention) on wednesday. I wonder if there is any chance that people will start to refer to this as For Sci Con or FSC for short...
One noticeable improvement was that the conference organizers had many bulletin boards available to the "public". In recent years there have been as little as 3, covered with junk.
The cybercafe was also terminal plentiful, and not that crowded. Perhaps it was just due to the time of day. Perhaps it is due to the fact more and more people have their own laptops... or netbooks. I didn't try out the wifi in the convention center (if it exists). I'm in a hotel that is a couple blocks from the convention center and notice that there is something called DowntownDenverWifi. Great! Except i can't get the DowntownDenverWifi to work. maybe it is just my laptop...
One potential non-improvement is the poster session. My complaint is that the posters are usually too close together. there isn't enough room to move around. Tonight, the 31 toxicology posters were neatly arranged in a closet. at least they took the coats out. when i left, i was wearing someone else's shoes... i don't know what that means.
the denver convention center is very nice and i was impressed with the 16th street mall. for those who never have been to denver the 16th street mall is basically where 16th street is closed to traffic for 6 or so blocks (except for the buses). shops and food, etc.
And the new AAFS webpage is really nice.
Monday, February 02, 2009
by blogger gmp
Advances in DNA testing continue to lead to the exoneration of convicted felons, many of whom would otherwise be imprisoned for the duration of their lives. This same technology has led to the "correct" arresting and imprisonment of the associated perpetrators, furthermore validating this means of suspect identification and prosecution. Some of the issues with this system involve the most commonly encountered reason for not pursuing all means of finding "reasonable doubt" - funding. Because of the distribution of wealth within states and the country, many people currently in jail could be freed if only their district had the finances.
|After spending nearly 27 years buried in the vast Texas prison system for a crime he did not commit, Charles Chatman's first weeks of freedom have been overwhelming.|
Each of the six rooms in his new apartment, including the bathroom, is larger than any of his previous cells. The gleaming entertainment system and sleek laptop from family, friends and attorneys might as well be hollow props on a movie set, because Chatman, 47, has little idea how to operate them — testimony to more than a generation lost behind bars.
Chatman was exonerated last month by DNA testing while serving a 99-year sentence for sexual assault. .
Hope remains that the government will intervene and assist more counties in research such technology prior to the conviction of any suspects, else more lawsuits against cities and counties may arise for wrongful arrest.
by blogger cos
A UK forensic scientist at the University of Leicester has found that sweaty fingerprints which are high in salt content will leave more of a corrosive impression in the metal they are deposited on. The more corrosive prints can be easily visualized using a novel technique which could help in solving crimes in the future and previously unsolved cases. The connection has been made to processed foods because they are generally high in salt. As a result criminals, who have a diet high in processed foods are more likely to be discovered using this novel technique.
|Dr John Bond, a researcher at the University of Leicester and scientific support officer at Northamptonshire Police, said processed food fans are more likely to leave tell-tale signs at a crime scene.|
Speaking before a conference on forensic science at the University of Leicester, Dr Bond said sweaty fingerprint marks made more of a corrosive impression on metal if they had a high salt content.
And he revealed he was currently in early talks with colleagues at the University of Leicester to assess whether a sweat mark left at a crime scene could be analysed to reveal a ‘sweat profile’ ie more about the type of person who left the mark...
...Dr Bond said: “On the basis that processed foods tend to be high in salt as a preservative, the body needs to excrete excess salt which comes out as sweat through the pores in our fingers.
So the sweaty fingerprint impression you leave when you touch a surface will be high in salt if you eat a lot of processed foods -the higher the salt, the better the corrosion of the metal."
by blogger CS
Scientists are using the unique genetic sequence inherent to microbes, they can tell the difference between related strains of bacteria. It is claimed to be as remarkable as human DNA, even being able to identify the culprits of food poisoning. The techniques utilized are much like the same techniques used by the CDC to identify a disease. This research stemmed from the anthrax attacks from years passed. Investigators were able to link some of the biological attacks to an individual based on the genetic fingerprint of parent spores found in a flask. They claim to be able to trace a single vial of "germs." Speaking realistically, it seems as though this is better in thought than in practice. Perhaps this form of genetic fingerprinting will become more useful than any other practice currently being used in forensics, but for now it's still too soon to tell.
|Microbial forensics is "still a field very much in its infancy," said prominent gene researcher Dr. Claire Fraser-Liggett...Unlike in 2001, today the genetic makeup of many bacteria and viruses has been fully sequenced, or decoded...So Fraser-Liggett urges development of a database of multiple samples of pathogens collected from around the world, so the next such investigation won't have to start from scratch...But legally, microbial forensics raises enough issues that in 2004, the FBI created an elite committee of specialists in genetics and law enforcement to develop the first guidelines on how to handle and preserve bacteria or viruses that may be part of a crime.|
This would be incredible, but a lot of convincing in the science world needs to be done. If this becomes a tried and true practice, we can just add it to our ever expanding forensic tool belt.
by blogger jld
GHB was a drug initially developed to treat illnesses such as anxiety, depression and sleep disorders. Recently it has been abused as a recreational drug and more violently as a date rape drug. Researchers in the UK have been developing a method to invent a portable Raman Spectroscopy test as well as a bench test to detect GHB and GHL in alcoholic beverages as well as storage vials. They tested different storage containers that could be used to hold GHB as well as variations in type and concentration of alcoholic beverages. They concluded that it was a useful method to test for GHB in the field to compliment more thorough tests done in the laboratory.
|Forensic analysis usually relies on high performance liquid chromatography (HPLC), gas chromatography coupled with mass spectrometry (GC-MS), nuclear magnetic resonance or infra-red spectroscopy. Moreover, it usually requires the extraction of the drug from a suspect sample before analysis is possible. Raman spectroscopy, on the other hand, is a quick and simple, non-destructive technique that provides qualitative and quantitative information. It might therefore be used to identify substances at the scene of crime or at customs inspection points at shipping ports and airports. The sample need not be removed from the transparent container in which it is found. |
"We are able to detect GHB and GBL in a variety of containers including colourless and amber glass vials, plastic vials and polythene bags," explain the researchers, "We have also demonstrated the ability to detect both GBL and GHB in a range of liquid matrices simulating spiked beverages." The lower concentration limit was 1% w/v, which is significantly lower than the common dosage level the team says.
"This work clearly demonstrates that portable Raman spectrometers can be used to interrogate samples in situ," the researchers conclude, "allowing a more thorough investigation of key samples by Raman and other analytical techniques in a forensic laboratory where applicable."
It seems that this new portable system may be useful in airports or property searches but it does not have much practical use once a crime has been committed. The chances of finding a left over drink to test for GHB after the victim has left a bar or a party are pretty slim.
by blogger jmj
The State of New York has spent $7 million dollars since 2001 to test fire new handguns and enter the minute markings the guns make on the shell casings into a searchable database. Proponents contend that the unique markings left behind can later be compared to shell casings found at crime scenes. However, with over 200,000 "fingerprints" in the system, the database has yet to lead to a criminal prosecution.
Opponents to the database argue that the markings left by the gun change over the long term and can be deliberately altered. They also point out that the majority of guns involved in crimes are not used by their legal owner, but are stolen or otherwise obtained by the criminal. They conclude that the amount of money and time dedicated to the record keeping of every gun sold is a wasted effort since less than one percent of all guns sold will ever be used in a crime.
Politicians in Albany however need only direct the attention of these naysayers to Maryland where a similar system has been in place since 2000. With only one more year under their belt than New York, Maryland already has one conviction to their credit.
|Seven years ago, New York started a database of "ballistic fingerprints" for all new handguns sold in the state. The bill's backers sold it as a crime-solving device, arguing that the state would now have a sample of a spent shell and bullet for every new gun sold. This, they said, would help police connect future evidence from crime scenes to specific guns. |
Since then, the authorities have entered 200,000 newly purchased guns into the database and spent $1 million dollars a year on the system. Yet it hasn't led to a single solved crime. The only other state with such a database, Maryland, can attribute at least one conviction to the system since it was created in 2000-more than zero, but few enough that the state's own Police Forensics Division has suggested scrapping the program because of its demonstrated lack of benefits.
2009... should be your year, New York!
by blogger chwb
Scientists have devised a way of connecting gun crimes back to a suspect. The groundbreaking technology...Pollen. What took Mother Earth millions of years to engineer, is being used by scientists to connect suspects back to the cartridge casings used at a crime scene. Scientist have enhanced the pollen by adding their secret formula of "titanium oxide, zirconia, silica, or a mixture of other oxides." I guess the ratio of ingredients and not the actual ingredients are the secret formula.
|The tags primarily consist of naturally-occurring pollen, a substance that evolution has provided with extraordinary adhesive properties,” says Professor Paul Sermon from the University of Surrey, who has led the research. “It has been given a unique chemical signature by coating it with titanium oxide, zirconia, silica or a mixture of other oxides. The precise composition of this coating can be varied subtly from one batch of cartridges to another, enabling a firm connection to be made between a particular fired cartridge and its user.|
So in the future super sleuths, look for the suspect with the sniffles and a box of Kleenex. It could be the smoking gun ;)
by blogger msb
Casemaking clothes moth caterpillars are mostly a rural dweller that will feed on human remains and can digest human hair. Entomologists have recently found that the larvae casings, which are constructed of nearby hair and fibers, can yield enough mitochondrial DNA to identify a corpse as well as link a body to the crime scene if it has been moved.
|Bucheli and her colleagues discovered human hair in caterpillar cases when a forensics team asked for help with an abandoned body discovered in August 2007 in a Galveston County, Texas house...The hair shafts yielded enough mitochondrial DNA for Bucheli and her lab to sequence a repetitive bit of genetic material commonly used for forensic identification.|
Sunday, February 01, 2009
by blogger mem
Scientists at the University of Santiago de Compostela have developed software that can more accurately determine the Post-Mortem Interval (PMI) using vitreous humor from the eyes of cadavers. They measure the levels of potassium, urea and a DNA metabolite, hypoxantine. The numbers are then crunched in a program they developed to calculate the PMI. If the results are accurate, it could be very useful to forensic pathologists
|“The equations we have developed now make it possible for us to estimate the PMI more precisely than before, and provide a useful and accessible tool to forensic pathologists that is easy to use.|
The precision and usefulness of these two models have been confirmed by chemical analysis in more than 200 vitreous humour samples. The doctor and the two mathematicians who have performed the study have verified that the SVM method offers more precise data.”
by blogger aaa
Researchers at the Midwest Forensic Resource Center at Iowa State University are building a library of ink mass spectras to help identify ink of question documents. The new technique used is called Direct Analysis in the Real Time (DART). This process eliminates the extraction step, which saves time for forensic scientists. The new technique does not require the sample to be cut and it produces results of richer data. Another phase of this project is to develop computer software for the library. Overall, this project will yield better results and save time which will beneficial to all,criminals excluded.
|Researchers at the Midwest Forensics Resource Center at Iowa State University are building a library of ink profiles to help forensic scientists identify inks on fraudulent documents and other evidence. MFRC scientists will pair mass spectrometry with a new sampling technique called Direct Analysis in Real Time (DART) to reveal the chemical makeup of ink faster and in greater detail than ever before...|
...But, on top of saving time and preserving evidence, the DART method also yields richer data about ink samples than previous sampling methods. Initial tests of the DART system indicate that the mass spectra reveal more components of the ink than conventional mass spectra. Using DART, forensic scientists may be able to differentiate between inks like never before.