Friday, May 26, 2006

Catch Terrorists with Pollen!

submit by troym; comments by blogger jgl

"Waiter, there's a dandelion seed in my jihad!"

Federal investigators are using pollen to try to track and catch criminals and even terrorists. It's one of a number of new forensic techniques being explored in the wake of 9-11.

Vaughn Bryant looks at pollen for microscopic clues that could help solve a crime or even catch a terrorist.

The Texas A&M professor has pioneered the use of pollen as a forensic tool.

“One of the advantages that we have the bad guys, the crooks, don't realize that their clothing, their hands, things that they come in contact with are picking up these little microscopic pollen grains that they don't even see,” Bryant said.

All of the pollen that people are breathing in is also landing on our clothes, landing on the ground. So the pollen at A&M is going to produce a pollen print as we call it kind of like a DNA, which is going to be fairly unique to the one area.

In theory, this is a good idea. As long as an expert doesn't get on the stand and say, "The pollen print at the crime scene and the pollen print on the suspects trousers were a *match*." This is one of those areas where quantifying what a *match* means might be tough. Is it specific to a city? A neighborhood? Someone's yard? And how much does it remain consistent over time?

But I guess that is what research is for... This would be good project to conduct in many different geographical locations with the help of a lot of investigators. It's a shame that any old idiot/lab monkey couldn't do this. It seems like only a very experienced botonist would have the skills to conduct the analysis.

Wednesday, May 24, 2006

Relative DNA: Good Policing or Good Harassment?

submit by troym; comments by blogger jgl

Articles like this have been all over the news for a couple weeks now. NPR did a fine story on it here. Troy sent in this article and made the point "using DNA profiles of a suspects' family members in criminal investigations (is this not a civil liberties issue)?" It is.

Victims of mass tragedies such as Hurricane Katrina and the World Trade Center attacks are often identified using the DNA of surviving relatives. Now, scientists say the same technique could help nab criminals.

When crime scene evidence does not match anyone in the criminal DNA database, investigators could also check for close matches. These near misses could be close relatives of the suspect, said forensic mathematician Charles Brenner of DNA-VIEW in Oakland, a visiting scholar at UC Berkeley.

A relative's match would not provide any direct evidence for building a case against a suspect, but it might provide new leads.

"It could be beneficial," said Sgt. Brian Dickerson of the Richmond Police Department's family services unit. "Anything that gives us additional leads would be good."

"There's obviously a balancing act between privacy and public safety," said John Tonkyn at the state DNA lab in Richmond.

Here is how it works. DNA found at a crime scene does not match any criminals in the database. However, it might "closely match" 5 criminals in the database. So in theory, the guilty person could be a brother/son/relative of any one of the 5 criminals.

The technique can definitely be beneficial for investigators, but essentially it creates a somewhat random pool of "potential offenders", all but one of whom is innocent (or all of whom are innocent). So the downside is that the police have an "excuse" to bother a bunch of people that had nothing to do with the crime. In theory, the police would never abuse this power, but a similar thing happened to Brandon Mayfield when his fingerprint almost matched that of the Madrid train bomber.

For the DNA analysts out there... i first heard about this being used with CODIS STRs. In the article, the focus is on using Y-STRs. it seems like this would be worse (create a larger pool and requires extra testing). thoughts?

Thursday, May 11, 2006

Duke DNA (mitochondrial?)

by blogger jgl

They don't some out and say it, but i assume they got some mtDNA from the fingernail scrapings. You'd think some mini-STRs could turn up something a little more "incriminating".

How would this work, did NC do the extractions and attempt STRs, then sent the extractions out for mtDNA anaysis? Or did they do mtDNA in the state lab? or did they send some of the scrapings out for extraction and analysis?

This will be interesting to follow. What's the latest verdict on how the jury perceives mtDNA evidence?

DURHAM, N.C. - Forensic scientists might have found a DNA link between a Duke lacrosse player and the female stripper who alleges she was raped at a players' house party March 13-14, the Durham Herald Sun reported Thursday.

Scientists have found tissue under a fingernail of the woman, which scientists concluded originated from the same gene pool and was "consistent" with one of 46 lacrosse players who gave DNA samples, the Herald Sun reported, citing sources.

Murder Mystery Dinner Theater with a Forensic Twist (sort of)

submitted by johndaly; comments by blogger jgl

John Daly sent this link. I think this type of project is a good idea for forensic professionals/students to work on. Great for public relations with local science centers and the public. Maybe even a revenue generator.

A murder has taken place at the Koshland Science Museum and you need to solve the crime! Interview suspects and collect evidence with forensics experts, including a medical examiner, a first response officer, and fingerprinting and firearms specialists.

What happened the night of the crime? How did the victim die? Who committed the crime? Using techniques that expert investigators use to solve real crimes, these are the questions you will answer as you solve the crime.

Fingerprint Images vs. Minutiae Templates

submitted by troym; comments by blogger jgl

Troy found this little story. I know very little about the fingerprint matching process. I thought that "minutiae templates" were used in the current method. It is interesting how they mention that vendor software is not cross-compatible. Is there room for improvement with the current fingerprint database system, or is it working out alright as it is?

A study by the National Institute of Standards and Technology (NIST) shows that computerized systems that match fingerprints using interoperable minutiae templates--mathematical representations of a fingerprint image--can be highly accurate as an alternative to the full fingerprint image.

Minutiae templates are a fraction of the size of fingerprint images, require less storage memory and can be transmitted electronically faster than images. However, the techniques used by vendors to convert fingerprint images to minutiae are generally proprietary and their systems do not work with each other.

Results of the test are available at

Tuesday, May 09, 2006

Cornwell Challenges You!

by blogger jgl

I rarely read forensic books, and don't really care for forensic movies or television shows... but I have to give Patricia Cornwell credit for a nice website. The headline link goes right to her "Forensic Challenge", which is a neat little educational tool. This is a good idea for instruction at the high school or undergraduate level.

Perhaps the forensic community could produce and share videos like these. Otherwise, some stupid "educational tool" company will do it and try to charge 300 bucks for a dvd.

Friday, May 05, 2006

Forensic Tequilaists

by blogger jgl

Happy Cinco De Mayo!

Whether you’re celebrating Cinco de Mayo or just having another relaxing day in Margaritaville, you might one day thank a chemist for assuring the authenticity of your tequila. New tests developed by scientists in Mexico and Germany will help distinguish the real thing from fraudulent versions, which are a potential threat as this alcoholic beverage grows in popularity.

Using ion and gas chromatography, scientists analyzed 31 tequila samples of the 100 percent Agave category and compared the results to 25 mixed-tequila samples. The pure Agave tended to have significantly higher levels of certain chemicals, including methanol, 2-methyl-1-butanol, and 2-phenylethanol, allowing them to be chemically distinguished as real, high-quality tequila, the researchers say. Although methanol was present, levels were small and did not reach toxic levels, they add.

In addition to these new tests, a screening test using Fourier Transform Infrared Spectroscopy (FTIR) may be used to identify fake tequilas from the real thing, the researchers say. The process, also known as molecular fingerprinting, takes only two minutes, they say. In general, the strategy of combining different spectroscopic and chromatographic methods is more accurate than previous identification attempts, which focused on other chemicals or the isotopic composition found in tequila, the researchers say.

Thursday, May 04, 2006

Deputies not poisoned by meth!

submitted by troym; comments by blogger jgl

Doesn't the headline and story just say it all?

Nobody slipped methamphetamine into a Sarpy County deputy's meal at an Applebee's restaurant, authorities said Friday.

Two Sarpy County sheriff's deputies said they became nauseated and disoriented after eating at the Papillion Applebee's on March 12.

The deputy's illness resulted from an adverse reaction to medication, Davis said.

The other deputy who became ill had not tested positive for meth, but Davis said investigators could not determine what caused the second deputy's illness.

"There are just some things you will never know," Davis said.

Even if you read the entire article (click on the blog headine above), there is still something missing here. The faulty first test originally showed meth was in the officer's food. This begs the question, does the Omaha lab perform comprehensive food analysis everytime an officer gets a tummy-ache? My guess is one of the officers had a beef with one of the cooks.

Wednesday, May 03, 2006

Lie Detectors (still) Don't Work!

Submitted by TroyM; comments by blogger jgl

Everybody knows that polygraphs don't work. With the possible exception of talk show hosts, the public, police, lawyers, and polygraph examiners.

In addition to the original article, John Daly has blogged some good material on the perception of infallibility of the forensic field.

The CIA, the FBI and other federal agencies are using polygraph machines more than ever to screen applicants and hunt for lawbreakers, even as scientists have become more certain that the equipment is ineffective in accurately detecting when people are lying.

Instead, many experts say, the real utility of the polygraph machine, or "lie detector," is that many of the tens of thousands of people who are subjected to it each year believe that it works -- and thus will frequently admit to things they might not otherwise acknowledge during an interview or interrogation.

Many researchers and defense attorneys say the technology is prone to a high number of false results that have stalled or derailed hundreds of careers and have prevented many qualified applicants from joining the fight against terrorism. At the FBI, for example, about 25 percent of applicants fail a polygraph exam each year, according to the bureau's security director.

In the popular mind, fueled by Hollywood representations, polygraphs are lie-detection machines that can peer inside people's heads to determine whether they are telling the truth.

The scientific reality is far different: The machines measure various physiological changes, including in blood pressure and heart rate, to determine when subjects are getting anxious, based on the idea that deception involves an element of anxiety. But because an emotion such as anxiety can be triggered by many factors other than lying, experts worry that the tests can overlook smooth-talking liars while pointing a finger at innocent people who just happen to be rattled.

25%! 25%! Somebody warn Maury Povich! I have a chip on my shoulder over this as I've had my career negatively altered because of this crap. I particularly like how they say the real utility is that people "believe" it works. Using this thing on applicants for forensic scientist positions is like placing a 40-year-old cynic on Santa's lap. (or something like that).

Tuesday, May 02, 2006

Bigfoot Debunked!

submitted by TroyM; posted by jgl

Finally, forensic science being put to good use.

That’s why Moody, a 57-year-old forensic biologist at Ohio University, didn’t automatically dismiss numerous Bigfoot sightings in Ohio through the years until he investigated one particular event.

Now, Moody says he thinks that Bigfoot sightings in Ohio are nothing more than myth.

The owners of the property where the sighting occurred had just had a load of gravel spread. Afterward, it rained and water flowed down the lane, picking up pieces of gravel, stirring eddies and digging little trenches.

"These were being interpreted as toe impressions," Moody said.

The hair turned out to be from a whitetailed deer.

Thanks for the story, Troy. I think fun stuff like this at universities is great.
And i'm not just saying that because i am an OU graduate and Athens lover.

Male Contraception, Forensic Concern?

by blogger jgl

Well, i guess it's a stretch to say that rapists would use this pill to hide sperm, since DNA can still be obtained. I don't know... Professionals, does lack of sperm make it difficult to get a profile? Still, presence of sperm is an issue in forensics, so i guess this is worth noting.

A contraceptive pill for men could be a step closer according to a study in male fertility.

But a study has found that men actually regain their full potential within a few months when treatment with the drug is stopped.

Up until now, the only long-term option for male contraception has been the vasectomy.

Nun Case - Relying on Lee and Blood Pattern?

by blogger jgl

Isn't this type of pattern comparison the definition of junk science? Why was this even presented in court?

A renowned forensic expert testified Thursday that a bloody stain on an altar cloth might link a priest to the death of a nun in 1980.

Dr. Henry Lee, who analyzed evidence and helped reconstruct the killing for the prosecution, said the stain had characteristics similar to those of a medallion on a letter opener that prosecutors say was used to kill Sister Margaret Ann Pahl in the chapel of Mercy Hospital.

He pointed at an enlarged photo of a blood stain and drew the jury's attention to what he said looked like the dome outline of the Capitol.

"The size is similar, the shape is similar, the diameter is similar," he said. He would not, however, call it an exact match.

I'm sure the jury is carefully weighing the "not exactness" of it.

Forensic Headline Example

by blogger initials

This is where your comments go.

Put the quote from the article here. Put the quote from the article here. Put the quote from the article here.

This is where additional comments can go.

Bloggers - use this code

<img width=250 style="border: 2px solid black" src="">
<span style="font-size:85%;">by blogger jgl</span>

This is where your comments go.

<table style="background-color: rgb(143, 182, 141); padding: 15px; border: 4px ridge rgb(93, 132, 91); font-style: italic" ><tbody><tr><td>Put the quote from the article here.</td></tr></tbody></table>
Put additional comments here.