122nd SEMI-ANNUAL SEMINAR (Fall 2013)
CALIFORNIA ASSOCIATION OF CRIMINALISTS
October 23-25, 2013
Modesto, California

THE SOUND OF SHOTS
Nancy McCombs, California Dept. of Justice Fresno Laboratory

A request was made by the Deputy District Attorney assigned to a double homicide case to estimate in a controlled Laboratory study how quickly a gun could be fired by one shooter then passed off to and fired by another shooter. Assistance with this case was provided in order to determine if an eye witness account of two shooters passing one gun was credible, or if one shooter acting alone was more likely, by examining actual shots recorded during a 911 call.

Multiple variations replicating how the shooting may have occurred were both audio and video recorded using a Nikon® DS300s camera. The time lapse between these shots and shots from the 911 call were then calculated using Audacity® recording/editing software and compared.

Further research was performed to correlate the recording capabilities of common cellular phones, which could be used to witness a shooting, as well as readily available recording/editing.


DEVELOPMENT OF A 3D-TOPOGRAPHY SYSTEM FOR FIREARM IDENTIFICATION USING GELSIGHT AND FEATURE BASED CASE MATCHING
Todd Weller, Ryan Lilien, Marcus Brubaker, Oakland Police Dept. Crime Laboratory

Despite the importance of toolmark analysis in the forensic sciences, the imaging and comparison of toolmarks, remains a manual and time consuming endeavor. The overall goal of our project is the development of an accurate and low-cost system for structural 3D imaging and comparison of cartridge cases. Our platform utilizes the recently developed GelSight surface topography imaging system and custom feature-based image comparison software. Our system's preliminary results from scanning and matching cartridge cases are extremely promising. In collaboration with computer science, engineering and forensics experts, we are working to improve our hardware and software, and conduct several moderate scale experimental benchmarks.

Our novel 3D imaging technology and structural analysis algorithms show extremely promising early results. We examined test fires collected from forty-seven 9mm Luger caliber firearms, using three different types of ammunition and performed over 27,000 inter-comparisons. Our research provides objective support of firearms identification and shows the potential of incorporating cutting-edge computer science algorithms into pattern matching analysis. Additionally, the data from our system provides further insights into firearm produced marks (such as the the size of marks on breech faces and quantifiable differences between brands of ammunition). These results demonstrate that our case matching algorithms are both fast and accurate. It is our hope to continue development of a general purpose case-matching system with a robust and statistically significant match score.


THE CLACKAMAS TOWN CENTER SHOOTING
Dan Alessio, Oregon State Police Metropolitan Crime Lab

On December 11, 2012, a gunman entered the Clackamas Town Center Mall and opened fire. This presentation will cover events leading up to, during, and after the shooting incident.


RE-WORKING COLD CASE EVIDENCE: ONE CRIMINALIST'S APPROACH
Dianne Burns, California Dept. of Justice Santa Barbara Laboratory

You are assigned an "unsolvable" thirty-plus year old case. It's been previously worked - several times over by a variety of agencies. What's an effective game plan for reexamining the evidence once again? CA DOJ Santa Barbara criminalist Dianne Burns' approach and methodology for screening the evidence is presented within the context of a 1981 double homicide that occurred in a residence on a sleepy cul-de-sac in Goleta, CA.


MENDOCINO COUNTY MURDER SOLVED AFTER 25 YEARS
Meghan Mannion Gray, California Dept. of Justice Richmond Laboratory

This case presentation will highlight the need for communication, patience, and creativity when working old and cold homicide cases.

Georgina Pacheco, 20, was last seen on September 1, 1988 leaving her shift at the Sea Pal Restaurant in Fort Bragg, CA. Her naked body was found in thick brush on a remote road on September 10. She had been raped and strangled. In the years since her death, many leads were followed and eliminated. Evidence was examined and consumed with no results and the case was eventually shelved with the hope that future technological advances might help to solve it. The case was reopened and assigned to me in 2010. Many hours were spent discussing the remaining evidence available, what work had previously been performed, and the best path forward. This investigation was truly a collaborative effort, relying on open communication between the DNA laboratory, the screening laboratory, and the detective assigned to the case. After reopening the case, it took three years, nine case reports, multiple technologies, creative thinking, and perseverance to reach the resolution. In 2013 biological evidence linked the victim's deceased brother-in-law to the crime and the Mendocino County Sheriff's Office declared this old and cold case closed.

The unsolved murder of Georgina Pacheco haunted the small community of Fort Bragg for nearly 25 years. Although the resolution left the family of this young woman with new questions, it also brought a sense of closure to those who loved her and the community to which she belonged.


PEOPLE V JASON GILLEY
DDA Robert Himelblau, San Joaquin County District Attorney's Office

On August 7th, 2011, after a night out with friends, Dalene Carlson, 23, was last seen leaving a local bar in Stockton. For 70 days Stockton Police looked for her, with the help of the FBI and Sheriff's Department. The question of whether she would be found alive was answered on October 15th, when a local farmer found her decomposed body in a corn field. A multitude of forensic science disciplines - Odontology, Pathology, Crime Scene Reconstruction, Firearms Examination, and Cell Phone/Tower Analysis - came to bear on the prime suspect, Jason Gilley. This case study will recount the intersection of these disciplines and their introduction to a jury charged with deciding who Dalene Carlson's murderer was.


ESTABLISHING AND MINIMIZING UNCERTAINTY OF MEASUREMENT IN WEIGHING
Thomas Rohrer, Mettler Toledo

The presentation, offered by Mettler Toledo's weighing experts, will focus on the key factors that will help bring your laboratory's weighing and data collection processes into alignment with globally established Good Weighing Practices and ensure the accuracy (and thorough and efficient recording) of data. The key areas covered will be the four influences of uncertainty of measurement in weighing and the common influences of error in the weighing process.

The popular Good Weighing Practices (GWP) and LabX Balance Excellence from Mettler Toledo helps eliminate the risk associated with weight measurement uncertainty by providing all components required by ISO 17025, including the quality management support you need so your weight accuracy can't be questioned.


OUTRAGEOUS!
Raymond Davis, Courtskills

Have you ever had the opportunity to know what every person's role was going to be in a major case? That is, what each prosecution and defense witness was going to testify to? Further, that you also knew the trial strategy of the prosecutor and defense attorney? Let's not forget about the physical evidence being introduced at trial. That you were aware of the types of evidence collected and analyzed. Are you that person? Have you been fortunate to have had that type of experience? Do you know anyone who has had that opportunity? If so, make them your friend.

I feel safe in saying that over 95% of the CAC membership has never been in a position to know every element in a major case trial. I am concerned about our role in the criminal justice system when we are never made aware of what transpires in most trials. Why?

That is the purpose of my presentation. To relate a homicide case I worked on many years ago where I saw the collision between legal and forensic ethics first hand leading to a miscarriage of justice.


CRIME LABORATORY: WHEN DRUGS GO MISSING-CRIME LABORATORY STUDY
John Yoshida, California Dept. of Justice Bureau of Forensic Services

The talk will discuss steps taken in the investigation of found drugs, into missing drugs and addressing the need to get ahead of the public and the media. We will also discuss the preventive measures applied to the Bureau's laboratories in increasing the quality control of cases. These include weighing envelopes, reanalyses, and instituting policies which cover additional documentation of analyses. We will also discuss the transparency of the process to the District Attorney Offices.


WHEN PUSH COMES TO SHOVE - THE ETHICS OF STANDING YOUR GROUND
Jennai Lawson, California Dept. of Justice Central Valley Laboratory

A fairly straight forward recent homicide case not initially thought to involve much DNA evidence at all became a court battle between expert witnesses. The key arguments came down to interpretational issues (both of a mixture and of a single "peak") and quality issues. Some interesting defense tactics came to light during the trial that will hopefully spark a lively discussion on the ethics of how something is reported versus how it is portrayed on the stand.


DNA RECOVERY FROM AMMUNITION
Lawrence Blanton, Los Angeles Police Dept. Crime Laboratory

Analysis of ammunition, both fired and unfired, for touch DNA has been debated, due to its low success rate. Research of 98 touch DNA samples, from ammunition, profiled by the LAPD Crime Lab over a seven year period will be presented.


THE AFTERMATH OF THE TERRORIST ATTACK ON THE WORLD TRADE CENTER
Joe Blozis, Retired NYPD Forensic Investigations

A forensic perspective of the recovery efforts of the NYPD's Crime Scene Unit at Ground Zero involving a documentary titled "911 Crime Scene Investigators." The presentation will include the events from the morning of September 11, 2001 through present day including terror plots, analysis, and the transformation of the site as it is today.


FURENSICS: ANIMAL DNA IN CRIMINAL INVESTIGATIONS
Christina Lindquist and Teri Kun, UC Davis Forensic Veterinary Genetics Laboratory

While committing a sexual assault in a residential backyard, Rusfus Sito Nanez III rolled in some canine feces which later helped link him back to the victim's home resulting in his conviction. The Veterinary Genetics Laboratory Forensic Unit at the UC Davis School of Veterinary Medicine played a key role in the trial and conviction of this serial rapist. As the only crime laboratory in the world accredited for analysis of DNA from domestic animals, VGL Forensics serves a large and diverse clientele. The laboratory receives a wide variety of cases from all over the world, with sample types and species unlike those encountered by its human counterparts. Cases range from human-on-human crimes where dog or cat biological evidence links a suspect to the crime, to large-scale dog fighting, species identification, and animal cruelty cases. Recently, the laboratory worked with investigators in the United Kingdom on the first cat DNA case in that country. Additional topics will include the challenges of and recent developments in non-human forensic DNA analysis and how those challenges presented opportunities to advance the field through research, development, and publication pertaining to animal forensic genetics as well as the establishment of SWGWILD where best practices standards and guidelines have been released for non-human forensic testing. Over the last fourteen years, the laboratory has assisted in other high-profile cases and cold cases, examples of which will be presented.


PROSECUTION OF A SERIAL KILLER
DDA Dori Ahana, Marin County District Attorney's Office

This discussion will follow the investigation of Joseph Naso and the coordination of a multitude of agencies including the DOJ in conducting DNA and other testing crucial to the prosecution of this case. I will provide examples of testimony and issues raised during the examination of witnesses including criminalists. This talk will highlight some of the issues raised in cold case, multi-victim, and murder investigations.


EARLY INJURY DETECTION

The Contra Costa District Attorney's Office is spearheading the use of Early Injury Detection (EID) in the prosecution of misdemeanor violence cases, particularly those involving strangulation and other situations in which it may be helpful to detect injuries at an earlier stage than is currently possible. Due to the cycle of domestic violence, victims often become uncooperative within hours of the offense and refuse to allow follow-up photographs that are essential for prosecution. Furthermore, in cases where they have been strangled, victims rarely agree to seek medical help despite the dangerous nature of the assault. More refined EID techniques will impact the forensic community by promoting detection of possible life-threatening injuries while they are in the process of forming or which may not be visible to the naked eye due to darker complexions.

The presentation will focus on the possible use of thermo graphic cameras to capture and document inflammation occurring beneath the surface of a victim's skin. These images may corroborate a victim's statement and may allow for better recognition of internal damage. Early detection of these injures could result in better criminal investigations and help identify dangerous health conditions that have resulted from trauma that is otherwise invisible. To date, both UV & IR radiation have been used to detect and document domestic violence injuries. The EID group intends to implement a research program to assess the relative merits of these techniques.

The DA's office is partnering with the Human Rights Center at UC Berkeley to advance EID investigative techniques. Members of the EID group: Dr. Cristian Orrego, Forensic Program, HRC, Dr. Bill Green, CCFMTC, Dr. George Sensabaugh, Professor Keith Inman, CSUEB, Butte County Investigator Ross Pack, Robert M. Thompson, NIST, Raymond Davis, CourtSkills, Colleen Gleason, attorney and Aaron Laycook, attorney.


REAL LIFE "RAMBO"
Deborah Enns, California Dept. of Justice Eureka Laboratory

In August of 2011, a homicide victim by gunshot was found in Mendocino County. No significant forensic evidence was collected or observed by the agency at the time, and the suspect was unknown. Subsequent to the agency processing the scene, representatives contacted the DOJ Eureka Laboratory and were advised to return to the scene in an attempt to locate possible DNA evidence that could be associated to a suspect. The agency returned to the scene and collected a foil marijuana joint in a location they believed the suspect may have fired his weapon. A second homicide victim by gunshot was found in a different location in Mendocino County approximately two weeks later, and a representative of the DOJ Eureka Laboratory was called to assist in evidence collection. Amongst the evidence collected, was a foil marijuana joint. A witness to the second homicide helped identify the suspect, and the agency had reason to believe that the suspect had committed both homicides; however, the suspect was not located or apprehended. DNA analysis of swabs from the foil joints was performed by the DOJ Redding Laboratory, and the results confirmed the identity of the suspect and placed the suspect at both homicide scenes. Two homicides approximately two weeks apart with a suspect on the loose generated much public and media concern. Finding the suspect became the highest priority for the Mendocino County Sheriff's Office. A manhunt to locate the suspect was launched. The suspect was able to elude officers for approximately five weeks due to the suspect's apparent "survivalist" training and his familiarity with the terrain. The search for the suspect involved multiple agencies including Mendocino County SWAT, Humboldt County SWAT, Alameda County SWAT, U.S. Marshalls, other agencies, and the use of search dogs. The search for the suspect ended when he was killed by SWAT officers. His rifle was submitted to the DOJ Eureka Laboratory to use for comparison to cartridge cases collected at the second homicide scene and a cartridge case collected when the suspect fired upon a SWAT team during the manhunt.


THE SPEED FREAK KILLERS: CASE HISTORY AND CALAVERAS COUNTY VICTIM RECOVERY EFFORTS
Ronald Welsh, California Dept. of Justice Central Valley Laboratory

From 1984 to 1998 serial killers Wesley Shermantine and Loren Herzog preyed on victims in California's San Joaquin County and beyond, likely claiming more than 20 victims. This presentation will discuss the history of their crimes and Shermantine's subsequent manipulation of his victims' families, the media, and the general public. Finally, the role of cadaver dogs and other resources will be discussed in the recovery of two victim's remains, thirteen and twenty six years after their murders.


THE SPEED FREAK KILLERS: SAN JOAQUIN COUNTY MULTI-AGENCY VICTIM RECOVERY EFFORTS
Michelle Terra, California Dept. of Justice Central Valley Laboratory

This presentation will discuss the San Joaquin County Victim Recovery Efforts from confined spaces. For two families the recovery answered the twenty-six plus year question "Where is my daughter?" but left many other questions unanswered for those families and other families missing loved ones.


DEVELOPMENT AND VALIDATION OF THE YFILER PLUSTM PCR AMPLIFICATION KIT, A NEW HIGHLY DISCRIMINATING Y-STR MULTIPLEX FOR FORENSIC APPLICATIONS
Ellen Crone, Life Technologies

Y-chromosomal markers have proven useful in solving investigations where low levels of male DNA are present in a high female DNA background. An intrinsic limitation of Y-STRs compared with autosomal STRs is a reduced power of discrimination due to a lack of recombination throughout most of the Y-chromosome. Thus, in an effort to increase the power of discrimination we have developed a new 6-dye, 27-plex Y-STR system that includes the 17 markers from the AmpFℒSTR Yfiler kit plus 10 additional highly polymorphic Y-STR markers (DYS576, DYS627, DYS460, DYS518, DYS570, DYS449, DYS481, DYF387S1a/b and DYS533). These ten new loci include 7 rapidly mutating Y-STR loci which allow for improved discrimination of related individuals.

The new multiplex is a dual application assay designed to amplify DNA from extracted casework samples and database samples from storage cards and swab lysates via direct amplification. Compared to the previous Yfiler® Kit, the new multiplex shows improved performance in inhibited samples, faster time to results, admixed male and female samples at ratios >1:1000 and better differentiation in male:male mixture samples in high female DNA background. Additionally under optimized conditions, no reproducible cross- reactive products were obtained on bacteria and commonly encountered animal species. The haplotype diversity and discriminatory capacity calculations for several population groups will be presented, as well as father-son studies and validation studies demonstrating improved performance with challenging samples.


NIST ACTIVITIES THAT SUPPORT FORENSIC SCIENTISTS: COMMISSION, STANDARDS & PUBLICATIONS
John Jones, National Institute of Standards and Technology

The National Institute of Standards and Technology (NIST) has developed a large number of reference documents, tools and physical standards that support the forensic science community. The Forensic Science Program (FSP) within NIST conducts and coordinates research and provides technical services to address the needs of the forensic science community. NIST is currently engaged in many national forensic science activities that impact the forensic science community. This lecture will address the following activities:


FORENSIC TECHNOLOGY CENTER OF EXCELLENCE: MAKING IT REAL...MOVING TECHNOLOGY FROM R&D TO YOUR LABORATORY
Jeri Ropero-Miller, RTI International, Center for Forensic Sciences

RTI International (RTI) was first awarded the National Institute of Justice Forensic Science Technology Center of Excellence (FTCOE) in 2011 and was recently awarded a third option year that will continue through September 30, 2014. Through close collaboration with NIJ, the FTCOE partnership leverages its strengths, capabilities, and resources to contribute to improvements in the field by:

  1. serving as a partner for the criminal justice community and for NIJ,
  2. raising the level of functioning of forensic science in the criminal justice community,
  3. quickly identifying the changing needs and capabilities of the criminal justice community with respect to the forensic sciences,
  4. bridging the disconnect between criminal justice practitioners and the available technology, and
  5. preventing "unproven" technologies from being used in the field and presented in court.

The objectives of the FTCOE put forward by NIJ, include:

  1. determining technology needs,
  2. developing technology program plans to address those needs,
  3. developing solutions,
  4. demonstrating, testing, evaluating, and adopting potential solutions into practice,
  5. developing and updating technology guidelines, and
  6. building capacity and conducting outreach.

To fulfill these tasks the FTCOE facilitates the operations of TWG meetings, conducts gap analyses to identify technology needs, improves dissemination and support mechanisms to help the end user, and provides effective in-person technology-transition workshop content that will be accessible to individuals online. The FTCOE also leverages the experience and infrastructure of RTI's Web-based training program as a foundation for training and outreach proven to reach tens of thousands of stakeholders, both domestically and internationally.

This presentation will highlight activities in the areas of Technology Transfer and Research and Development over the last two years that support Criminalistics.


TO CATCH A TWEETER, THE USE OF SOCIAL MEDIA IN COURT
DDA Janet Smith, San Joaquin County District Attorney's Office

How social media is used during the course of criminal investigations to identify suspects, collect evidence and prove elements of gang enhancements.


FORENSIC ENTOMOLOGY: UTILITY, LIMITATIONS, AND EVIDENCE COLLECTION
Bob Kimsey, UC Davis Entomology Dept.

Have you ever found yourself in this situation?

You are at a crime scene and observe a lot of insect activity on and around the victim. You know that the insects could provide some useful information but you're not well versed on how best to preserve them, nor what that useful information might be. So, you throw a few token bugs into a vial and book them into Property, or worse yet, you don't collect them at all because you aren't aware of the resources available to even examine them.

Insect evidence often goes largely ignored in the forensic arena simply because it is a rare forensic speciality that many agencies don't know is available to them. Entomological evidence can often provide valuable information that should not be overlooked. Thus, I will discuss what forensic entomology is, the kinds of information entomological evidence can provide, as well as its limitations using a number of case examples. But most importantly I will describe the collection techniques that assure optimal preservation of entomological evidence.


DEVELOPMENT OF A TARGETED NEXT GENERATION SEQUENCING SOLUTION FOR FORENSIC GENOMICS
Anne C. Jäger, K. Stephens, J. Varlaro, and C.L. Holt, Illumina, San Diego, CA, USA

Sequencing (NGS) by Synthesis (SBS) enables the entire human genome to be sequenced in one day. Whole genome sequencing (WGS) provides access to all genetic differences between individuals, and is valuable in studying disease and biological systems. While WGS delivers the broadest genomic coverage, it also requires the largest sequencing and interpretation effort. As a simpler alternative, forensic scientists can choose to perform targeted sequencing of PCR products. By sequencing a dense set of forensic loci, casework and database efforts are directed toward the genomic regions that best answer forensic questions, relieving privacy concerns and simplifying analysis. Because it does not depend on allele separation by size, the number of targets interrogated is not limited, allowing a more comprehensive result to be generated.

We describe the development of a targeted amplicon panel for forensic genomics that combines a core of global short tandem repeat markers used routinely today, along with additional forensic loci that can provide information when standard markers would fail to sufficiently resolve a case. Maximizing the number and types of markers that are analyzed for each sample provides more comprehensive and discriminating information for standard samples, as well as challenging samples that contain low quantities of DNA, degraded and/or inhibited DNA, and complex mixtures. The targeted amplicon panel will enable more complex kinship analysis to be performed, and can also reveal phenotypic and biogeographical ancestry information about a perpetrator to assist with criminal investigations. This capability is expected to dramatically improve the ability to investigate dead end cases, where a suspect reference sample or database hit are not available. We will describe the workflow, and present data from early developmental studies with both standard and challenging forensic samples, along with concordance with standard capillary electrophoresis methods.


DEVELOPMENT OF A NEW BIOCHIP ARRAY FOR THE SIMULTANEOUS DETECTION OF 'DATE-RAPE' DRUGS AND METABOLITES IN URINE SAMPLES
Donald Chung, Randox Toxicology Limited

Introduction: Drug facilitated sexual assault (DFSA) is a subset of drug-facilitated crime and involves the administration of drugs and/or other intoxicating substance or alcohol which render an individual incapacitated, or incapable of giving or withholding consent. There is a growing arsenal of drugs, which are exploited for DFSA causing symptoms such as unconsciousness, conscious paralysis and amnesia. The effects of these drugs are often potentiated by alcohol. The aim of this study was to develop a biochip array applicable to the simultaneous detection of compounds implicated in DFSA: chloral hydrate metabolite, ethyl glucuronide, fentanyl, flunitrazepam, meperidine, meprobamate, 'Z-drugs', and their major metabolites in urine samples. Detection of metabolites as well as parent drugs extends the window of detection, which is relevant because some DFSA drugs have amnesic effects and the crime may not be reported for days or even weeks. Methods Simultaneous competitive chemiluminescent biochip-based immunoassays were employed. The capture ligands were immobilised and stabilised on the biochip surface defining discrete tests regions, the biochip was also the vessel for the immunoreactions. The assays were applied to the semi-automated Evidence Investigator analyser.

Results: The specificity profile of the array is summarised as follows: the chloral hydrate metabolite assay was standardised to trichloroethyl glucuronide (% cross-reactivity 100%). The ethyl glucuronide assay was standardised to this compound and also presented a % cross-reactivity value of 11.7% for methylethyl glucuronide. The fentanyl assay wasstandardised to norfentanyl; fentanyl and benzyl fentanyl were also detected (% cross-reactivity: 330.5% and 425.5 % respectively). The flunitrozepam assay was standardised to 7-amino-flunitrazepam and presented % cross-reactivity 58.6% with flunitrazepam. The meperidine assay was standardised to normeperidine and also detected meperidine (% cross-reactivity: 149.2%). The meprobamate assay was standardised to this compound but also detected carisoprodol (% cross-reactivity: 76.6%). Three distinct immunoassays were present on the biochip for the determination of Z drugs: zaleplon assay (target specific), zolpidem assay (detecting parent compound and zolpidem metabolite I, % cross-reactivity: 100% and 27.2% respectively), and zopiclone assay (zopiclone, N-desmethyl zopiclone, zopiclone-N-oxide, eszopiclone; % cross-reactivity: 100%, 120.5%, 111.6%, 25.4% respectively. The limits of detection (LOD) in urine were 0.22ng/ml (norfentanyl), 0.68ng/ml (7-amino flunitrazepam), 0.60ng/ml (normeperidine), 4.38ng/ml (meprobamate), 0.60ng/ml (zaleplon), 0.45ng/ml (zolpidem) and 2.95ng/ml (zopiclone), 0.18µg/ml (chloral hydrate metabolite) and 0.16µg/ml (ethyl glucuronide). LODs met guidelines for minimum performance limits set out by the Society of Forensic toxicologists (SOFT) where provided.

Conclusions: This biochip array represents the first analytical system capable of the simultaneous detection of chloral hydrate metabolite, ethyl glucuronide, fentanyl, flunitrazepam, meperidine, meprobamate and 'Z-drugs' as well as their major metabolites in urine samples. The detection of parent compound and metabolites increases the window of detection. This biochip array is a valuable analytical tool in establishing the presence of these drugs in urine samples from suspected DFSA incidents.


QUALITATIVE ANALYSIS OF INHALANTS IN A BLOOD BY HS-GC AND GC-MS
Vincent Keokot, California Dept. of Justice Central Valley

A 36 year-old female was involved a traffic collision. There were five to six cans of compressed air, including one which was on the driver's seat that was frosty and cold to the touch indicating that it had been recently used. She admitted to the investigating officer that she had been sucking air from aerosol cans.

1,1-difluoroethane (Freon 152a) and 1,1,1,2-tetrafluoroethane (R-134a) are newly introduced propellant and refrigerant found in a variety of commercial products including aerosols. Because of its euphoric effect, availability, and low cost, these compounds have become a substance of abuse. Numerous cases are reported each year to the American Association of Poison Control Centers related to 1,1-difluoroethane. A routine forensic alcohol analysis revealed an unknown volatile compound in her blood specimen, providing an opportunity for qualitative analysis of 1,1-difluoroethane and 1,1,1,2-tetrafluoroethane by Headspace-Gas Chromatography and Gas Chromatography-Mass Spectrometry.