The applied research development objective is to support public crime laboratories by designing and testing research in the application of advanced technology to forensic services. Here are some examples of CFSI-supported research efforts.
Dr. Katherine Roberts and Donald Johnson
Donald Johnson. “Isolation and Individualization of Conceptus and Maternal Tissues from Abortions and Afterbirths for Parentage Testing”, accepted, Journal of Forensic Sciences.
Professors Johnson and Roberts conducted NIJ funded research with Dr. Rolf Müller, Founder and CSO of Biomatrica, Inc., on the effectiveness of SampleMatrix™ in the stabilization of biological evidence over conventional collection and storage methods
Controlled Study of the Recovery of Semen from the Vaginal Tract Post-Intercourse
Quantification of 6-Benzodiazepines in Blood using LCMS
Application of mRNA for Tissue Specificity of Crime Scene Samples
Evaluation of a “Re-usable” Gelatin Matrix for Firearms Reconstruction
Iranian Jewish STR Allele Frequency Distribution
Evaluation of PCRBoost to Enhance DNA Amplification & Improve Allelic Balance
Graduate Student Spotlight
CSULA Criminalistics Master’s student Jennifer De La Cerda is conducting a study to investigate the stability of semen stored in condoms over periods of time and subjected to various environmental conditions. Used condoms are routinely found at crime scenes. Spermatozoa are recovered from the seminal fluid in condoms for two reasons. First, spermatozoa are identified and confirmed by microscopic examination. Second, the genotyping of the spermatozoa serves to identify the semen donor, which may then indicate the guilty and exonerate the innocent. Spermatozoa recovered from recently used condoms still can be in poor condition, suggesting that condoms possess physical and/or chemical properties that can compromise the semen samples.
J. Edgar Hoover Scholarship Winner
CSULA Criminalistics Master’s student Alejandra Ramirez worked on a study that will help criminal and civil cases identify false documents, which computer technology has made easier to produce. Ramirez’s undergraduate thesis project focuses on using a commercial capillary electrophoresis instrument to analyze inks from ink cartridges, both directly extracted out of the cartridge as well as extracted from paper. Currently, the proper buffer in which the separation of ink components should take place is being determined.
Completed Research Projects:
Amplification Success Rate as a Function of Hair Morphology
Amplification success was assessed as a function of several independent variables: morphological characteristics; telogen root versus no root; donor age; scalp origin; use of cosmetic hair treatments; and race of the donor. The results show that a positive correlation exists between amplification success and the presence of a telogen root. Combining the amplification success with either the original or optimized protocol, telogen hairs result in an overall success rate of 77.5% compared with 65% for hairs with no roots. Controlling for telogen hairs, the findings indicate that the overall success rate is independent of cosmetic hair treatments; medulla structure; shaft length, diameter, and volume; and scalp origin. Conversely, the age of the donor, the race of the donor, and hair pigmentation all contribute to a variation in amplification success rate.
Published in Journal of Forensic Sciences. Vol 52 Issue 1 Jan 2007
Heteroplasmic Patterns Among Hairs from Single Individuals
For the purpose of this study a sample was scored as heteroplasmic if two probe signals were visible within a single probe region (either with equal or uneven intensity). The genetic diversity value for each population group was analyzed and the frequency of each mtDNA haplotype was determined. The results of this study demonstrate differences in heteroplasmic expression between hair and blood tissue. Further, differences in expression were also observed within each respective tissue. The study evaluates the frequency of heteroplasmy across racial population groups and notes that although the frequency is higher in the U.S. Asian and U.S. Caucasian population, there is no statistical correlation across all population groups.
Publication on Progress
MtDNA Heteroplasmy as a function of Hair Morphology
The results of this study suggests that the heteroplasmic condition does not differ significantly with cosmetic treatment, age, gender, medulla morphology, region of the scalp, hair growth phase, or, when comparing living and deceased donors. However, there does appear to be a correlation between heteroplasmy and hair pigmentation; typically, lighter pigmented hairs exhibit a higher incidence of heteroplasmy compared to darker hairs.
Publication on Progress