Scientific Evidence and Experts in a Military Court-Martial
Types of Scientific Evidence and Experts Common in a Military Court-Martial
Overview of scientific evidence experts:
Melendez-Diaz: confrontation right requires government to call witnesses who tested materials, if results are to be used in evidence; United States v. Blazier (Blazier II), 69 M.J. 218 (C.A.A.F. 2010).
- Experts may testify to meaning of machine-generated results.
- Complex and evolving area
DNA: Trial counsel: if you have it, get it tested, use it. Juries expect it, like it; “why not?” defense if untested; argue “what did you expect him to say, with DNA proving sex?” Can avoid using offender statement to prove sexual act element (you want offender on the stand).
Military defense counsel
Sometimes good for you. Never stipulate to it. Can be useful cross-exam witness:
talk to examiner:
- Where was it?
- Other way to be there?
- Transfer during innocent visit?
AUTOSOMAL STR DNA TESTING
Point: Autosomal STR analysis – inclusion, exclusion, inconclusive
Q: The human body is made up of trillions of cells?
Q: Deoxyribonucleic acid, or DNA, is located within the nucleus of many of these cells? Q. DNA is passed from parents to their children?
Q: DNA is the same throughout the body?
Q: DNA does not change over time?Q: DNA is responsible for instructing cells what to do and how to function?
Q: DNA is contained in chromosomes that are within the cell’s nucleus?
Q. Each person has 23 pairs of chromosomes?
Q. 22 pairs of autosomal chromosomes and one pair of sex chromosomes?
Q. Autosomal chromosomes are not involved in determining a person’s gender?
Q. Autosomal DNA is the primary focus of forensic DNA analysis?
Q. There are specific locations of forensic interest on autosomal chromosomes called loci?
Q: These genetic loci have short segments of DNA called STRs or short tandem repeats?
Q: These STRs are what forensic DNA examiners use to identify the individual source of biological evidence found at a crime scene or on an item of evidence?
Q. No two people will have the same autosomal STR DNA profile for all tested loci except identical twins?
Q: That is why autosomal STR analysis is a valuable tool in criminal investigations?
Q. It has high power of discrimination and can identify an individual?
Q: Autosomal STR analysis can be performed on biological material that contains nucleated cells?
Q. This includes body fluid stains?
Q: The two most common body fluid stains are blood and semen?
Q. Both are rich sources of DNA?
Q. Autosomal STR analysis is routinely performed on these body fluid stains?
Q: Autosomal STR analysis can also be performed on hair, tissue, and saliva?
Q. The first step of autosomal STR analysis is extraction, which is removing DNA from the cells?
Q. The second step is quantitation or determining how much DNA was extracted?
Q. The amount of DNA found on an item of evidence can be critical to understanding what took place during an alleged incident?
Q. For example, a trace amount of DNA indicates a person left behind a small number of cells, which could be due to them only touching an item for a short time?
Q. Or, their trace amount of DNA could have been transferred onto the item by someone else?
Q. Autosomal STR analysis is an extremely sensitive testing method?
Q. It can generate a DNA profile from less than ten cells?
Q. Because of its sensitivity, autosomal STR analysis can be used to detect DNA from skin cells on tools?
Q: Cartridge cases?
Q: Light switches?
Q: Or any other objects or surfaces at a crime scene?
Q. Autosomal STR analysis can include someone as the source of biological material found at a crime scene?
Q. Autosomal STR analysis can exclude someone as the source of biological material found at a crime scene?
Q: If a DNA profile obtained from biological material that was collected at a crime scene is different from a suspect’s DNA profile, then that evidence did not come from that suspect?
Q: If the evidentiary DNA profile is the same as the suspect’s DNA profile, then that individual cannot be excluded as the source of DNA found on the evidence?
Q: When a suspect cannot be excluded, a statistical analysis is done to determine the likelihood that the suspect is the source of DNA on the item of evidence?
Q: In autosomal STR analysis, there are three primary results when a DNA profile is compared to a victim or suspect?
Q: Inclusion, exclusion, or inconclusive?
Q. Inclusion means the evidence DNA profile and the known DNA reference profile are the same?
Q. Exclusion means the evidence DNA profile and the known DNA reference profile are different?
Q. An inconclusive result means there isn’t sufficient DNA data to create a profile?
Q: Or that the DNA data is uninterpretable?
Point: DNA analysis can’t determine how or when DNA was deposited
Q: In this case, the Defendant’s DNA was present on the alleged victim’s shirt? Q: The testing cannot determine how his DNA got there?
Q: It cannot tell us when his DNA got there?
Q: For example, if the Defendant’s clothing was collected and packaged with the alleged victim’s shirt, it’s possible that the Defendant’s DNA transferred onto the alleged victim’s shirt when their clothing was intermingled?
Q: It’s possible that the Defendant’s DNA transferred to the alleged victim’s shirt during casual, innocent contact between them before this alleged incident?
Q: For example, when the two of them were dancing together just hours before this alleged incident?
Real Costs of a COURT MARTIAL Conviction and Discharge
— any past sex w/ accused, that could explain it?
— cannot tell age of DNA
— tiny sample (5 cells) gives result
— can not tell what biological source (body fluid or skin cells) yielded DNA14}