Group items tagged

Dad pays teen $200 to quit Facebook

In 2012, readers searching for forensic science content now have many more ways to find

"The body chemistry of the person who left the fingerprint can tell us some things," said Shaler. "If the suspect is older or younger or a lactating mother, for example."The researchers used a form of physical vapor deposition -- a method that uses a vacuum and allows vaporized materials to condense on a surface creating a thin film. Normally, the deposition process requires exceptionally clean surfaces because any speck of dust or grease on the coated surface shows up as a deformity. However, with fingerprints, the point is to have the surface material's ridges and valleys -- topography -- show up on the new surface so analysts can read them using an optical device without the necessity of chemical development or microscopy."This approach allows us to look at the topography better and to look at the chemistry later," said Shaler. "We wouldn't have thought of this by ourselves, but we could do it together."One benefit of this approach would be the ability to retrieve fingerprints off fragments from incendiary or explosive devices and still be able to analyze the chemicals used in the device.The specific method used is a conformal-evaporated-film-by-rotation technique developed to create highly accurate copies of biological templates such as insect eyes or butterfly wings. Both are surfaces that have nanoscale variations."It is a very simple process," said Lakhtakia. "And fingerprints are not nanoscale objects, so the conformal coating is applied to something big by nanotechnology standards."

Investigators have found new DNA evidence in the murder of Peggy Hettrick, a case that was considered closed until genetic evidence freed a man who spent 10 years in prison, according to Colorado Attorney General John Suthers.The "touch DNA" tests weren't available in the late 1990s. Timothy Masters was convicted of murder in Hettrick's death in 1999, but his conviction was overturned in 2008 after defense lawyers used advanced DNA testing to uncover evidence suggesting a different suspect.The new evidence was taken from Hettrick's clothing. "We have done 'touch DNA,' and I think it has moved the ball forward. We will know more in the future," Suthers said. He wouldn't say whose DNA was found or identify the clothing on which it was found.Masters has not been exonerated in the case and remains a suspect."While we are not in a position to exonerate Tim at this time, I emphasize that he is presumed innocent and is no more a suspect than a variety of other people," Suthers said.