Powerful microscopes making life more difficult for criminals
Scanning electron microscope added to high-tech arsenal at URI
KINGSTON, R.I. -- November 8, 2001 -- It used to be that nabbing the bad guys meant having the fastest gun, the shrewdest detectives or getting the luckiest breaks.
But these days, state-of-the-art crime fighting now requires the best scientific equipment and top-notch scientists to run it.
The University of Rhode Island now has both thanks to the work of its scientists in the Sensors and Surface Technology (SST) and Forensic Science partnerships.
Otto Gregory (shown at right), professor of chemical engineering and co-director of the SST Partnership, and Michael Platek (at left in photo), electrical materials engineer and SST Partnership lab manager, have assembled one of the most advanced labs in the region for analysis of gunshot residue, trace evidence, pipe bombs, paint chips, textile fibers, and blood spatters.
URI scientists are also pooling the technology and brainpower of the two partnerships to develop new tools for preventing terrorism, including bioterrorism.
In putting together the laboratory, they relied heavily on the expertise of partnership colleagues from the College of Engineering, Departments of Chemistry and Physics and the Rhode Island State Crime Laboratory at URI.
In addition, the equipment will allow students involved in both partnerships to conduct research using the latest equipment.
The newest arrival is a $245,000, high-resolution scanning electron microscope (SEM) manufactured by JEOL, which was in part purchased through a $170,000 National Science Foundation grant awarded to Gregory. The University provided matching funds.
"This is a premier microscope because it includes a controlled vacuum system, which allows us to examine specimens in the near-atmospheric conditions from which they were taken by police," Gregory said.
"We can look at specimens of gunshot residue, rock, glass, polymers, fibers from rugs and clothes under direct examination in conditions that more closely match the environment from where they were taken," Gregory said.
Gregory said the lab has already completed more than a dozen paint chip analyses for such agencies as the state Crime Laboratory, Naval Criminal Investigative Service Cold Case Squad and the South Kingstown, Pawtucket and Rhode Island State police departments.
Scientists can now also provide gunshot residue and pipe bomb fragment analyses, work that could not be done in Rhode Island before the purchase of the new electron microscope.
"We are planning a new course within the Forensic Science Partnership that will focus on the applications of the SEM to analyze trace evidence," Gregory said. "Without the new SEM, investigating fibers, hair and other related trace evidence was only possible with lower resolution optical microscopes. The gunshot residue analysis feature will allow students, and local law enforcement personnel to be trained here in a unique area of scientific inquiry as well."
"Henry Lee (the world-renowned forensic scientist from Connecticut) endorses this equipment," Gregory said.
Gregory said the Rhode Island State Crime Laboratory has experienced an increase in requests for gunshot residue analysis since the FBI lab stopped providing it in 1995.
Gunshot residue samples taken by police from suspects skin, clothing and even upholstery from a car used in a crime are scanned over an 8- to 10-hour period by an electron beam that seeks out heavy metals found in the residue.
"The presence of a particular ratio of the elements antimony, barium and lead in a single particle is considered to be a unique signature for a gunshot residue specimen," Gregory said.
An important feature is the use of a single instrument to analyze particles and probe for elements particular to gunshot residue. "Other features, such as the non-destructive nature of the analysis allows the specimen to be re-examined as often as necessary," Gregory said.
Gregory said he is working on an unsolved murder case with the U.S. Naval Investigative Service that dates to 1975 in Middletown to see if the new microscope can provide additional information.
Gregory and Platek are also working with Chemistry Professors Jimmie Oxley and Jim Smith to use the electron microscope to examine pipe bomb fragments. "Pipe bombs are among the most common, most destructive and easily fabricated bombs used by terrorists today," Gregory said. "Based on correlations developed here at URI, fragment analysis investigations will assist evidence recovery teams to determine the exact size, nature of the propellants and construction of such devices."
In addition to working with the scanning electron microscope, Gregory and Platek are conducting research using a $100,000 atomic force microscope to determine whether it could be used to date the age of dried blood in murder cases.
Gregory and Platek are working with Don Housman of the Naval Investigate Service; URI Chemistry Professors William Euler, Chris Brown and Everett Crisman, an assistant chemical engineering research professor, on the project. Euler and Brown are using infrared spectroscopy to examine blood plasma to see how it changes over time to complement Gregorys, Plateks and Housmans work.
"We are all looking at cell changes, so that we can develop a more cohesive story," Gregory said. "We want to look at morphological changes and viscoelastic changes over time."
"No one has used the atomic force microscope for this type of analysis," Platek said.
Gregory and Euler are also using their expertise with an atomic force microscope to develop sensors for infrared devices that allow police and firefighters to see down dark alleys and through smoke-filled rooms.
"The expertise has always been here, and now we are learning new ways to solve problems," Gregory said.
Equipment used by Sensors and Surface and Forensic Science Partnerships
JEOL JSM-5900 LV scanning electron microscope
Electron Microscopes use a beam of highly energetic electrons to examine objects on a very fine scale, which can yield the following information:
oTopography: The surface features of an object, its texture.
oMorphology: The shape and size of the particles making up the object; direct relation between these structures and materials properties.
oComposition: Elements and compounds that the object is composed of and the relative amounts of them; direct relationship between composition and materials properties.
oCrystallographic Information: How the atoms are arranged in the object; direct relation between these arrangements and materials properties.
The scanning electron microscope (SEM) has become an indispensable tool in research, development, manufacturing and analysis. Applications include medical research and forensic science, environmental waste management and, semiconductor failure analysis.
Uses at the University of Rhode Island:
o Analysis of pipe bomb fragments
o Examination of textiles and fibers
o Gunshot residue analysis, explosive residue.
o Analysis of glass, soil, fiber, paint, building material and jewelry.
o Study of the biocompatibility of prosthetics
o Contamination of surfaces in material processing
o Bulk material analysis
o Study of corruption of computer chips
Park Scientific Autoprobe CP Atomic Force Microscope:
The atomic force microscope (AFM) probes the surface of a sample with a sharp tip, a couple of microns long and often less than 100Å in diameter. The tip is located at the free end of a cantilever that is 100 to 200µm long. Forces between the tip and the sample surface cause the cantilever to bend, or deflect. A detector measures the cantilever deflection as the tip is scanned over the sample, or the sample is scanned under the tip. The measured cantilever deflections allow a computer to generate a map of surface topography.
Forensic Uses at URI
o Blood spatter dating
o Quantifying surface tool marks in pharmaceutical market
Perkin Elmer PHI-5500, Multitechnique Surface Analyzer (Auger Electron Spectroscopy (AES), Electron Spectroscopy for Chemical Analysis (ESCA) and Secondary Ion Mass Spectroscopy (SIMS)):
AES is a technique that is primarily used on conducting materials. It can provide elemental information about the surface down to 0.1 atomic percent in accuracy and have a spatial resolution of 0.1 microns. It has the capability to dig a crater using an argon ion sputter gun and examine the film chemical properties as a function of depth. It is commonly used to identify failure mechanisms in integrated circuits, identify surface contaminants (metal processing, jewelry & semiconductor industry) and perform elemental chemical analysis of thin films such as high temperature strain gage sensors, thermocouple (temperature) sensors and/or humidity sensors.
ESCA is a technique that can be used on both conducting and non-conducting surfaces. ESCA can provide elemental and chemical information about the surface. Spatial resolution is 150 microns in area size. It has the capability to dig a crater using an argon ion sputter gun and examine the film chemical properties as a function of depth. It is commonly used to identify failure mechanisms in integrated circuits, identify surface contaminants (metal processing, jewelry & semiconductor industry) and perform elemental chemical analysis of thin films such as high temperature strain gage sensors, thermocouple (temperature) sensors and/or humidity sensors.
SIMS is a technique that can be used on both conducting and non-conducting surfaces. This technique involves collecting material that is removed with the argon ion sputter gun and analyzing this material with a mass spectrometer. SIMS can provide elemental and/or chemical information on the order of ppm (parts per million) range. It is a standard-less technique and has a spatial resolution of 300 um.
About the Partnerships
Sensors and Surface Technology Partnership
In 1996, the URI Sensors and Surface Technology Partnership was founded and currently consists of more than 25 faculty members from the departments of engineering, physics, chemistry, and food science, as well as faculty from several other universities. Its focus areas are micro-sensors, nano-fabrication and micro-structural engineering, coatings for corrosion resistance and integrated circuit research.
The partnership has built extensive relationships with corporations throughout Rhode Island and the United States. The University has provided the partnership about $375,000 in its first three years. These funds have been used to match more than $200,000 in equipment donations. In the past three years, the partnership has worked with more than 40 corporations and received more than $400,000 in external funding.
Building on the success of the partnership, faculty members helped to broaden the alliance to welcome new corporate members such as Shawmut Mills (West Bridgewater, MA) and Teltron Technologies Inc. (Birdsboro, PA) and other non-academic institutions such as the Naval Undersea Warfare Center and the Air Force Labs Sensors Directorate.
Forensic Science Partnership
The expertise of the scientific community at the University has been an invaluable resource for the Rhode Island State Crime Laboratory, providing an academic umbrella of support in the analysis of evidence and the courtroom testimony of laboratory personnel. In turn, the laboratory has worked with faculty from a variety of departments bringing them intellectually challenging and relevant problems, research support and public recognition. The URI Forensic Science Partnership was developed to formalize the historically established relationships among various URI departments (chemistry, engineering, textiles, geology, microbiology, botany and oceanography) and the Rhode Island State Crime Laboratory; aid in the development and promotion of the labs short courses; assist the faculty in expanding their research breadth to new areas and funding sources; and develop a foundation for the formation of forensic science courses.
The partnership is developing and promoting the concepts of forensic science to URI students beginning at the undergraduate level. Programs developed over the initial three-year tenure of the partnership will contribute to a formalized masters degree in forensic science. The partnership is also working to establish URI as the hub of forensic studies for law enforcement agencies in Rhode Island and throughout the northeast. Its goal is also to assist the faculty partners in providing research opportunities to undergraduate and graduate students in an interdisciplinary environment and enhance URIs prospects to be designated as a national center for forensic research and analysis.
For Information: Dave Lavallee 401-874-2116, Todd McLeish 401-874-2116