Forensic Statistics

Forensic Statistics is the application of probability models and statistical techniques to scientific evidence, such as DNA evidence and the law. In contrast to "everyday" statistics, to not engender bias or unduly draw conclusions, forensic statisticians report likelihoods as likelihood ratios (LR). This ratio of probabilities is then used by juries or judges to draw inferences or conclusions and decide legal matters. Forensic statistics uses several approaches for DNA statistics with computer programs such as; match probability, exclusion probability, likelihood ratios, Bayesian approaches, and paternity and kinship testing. Some of our example projects in forensic science can be found in Forensic Statistics.
One example of casework that a forensic statistician may be involved with is DNA profiling, which is a powerful method of identification using genetics. Often, the evidence to be evaluated involves human biological material such as blood, semen or vaginal fluid. Applications, however, are often not restricted to simple cases with one sample of DNA left at the scene of a crime and one suspect. Complications very often arise, for example because relatives may be involved, or the suspect may have been identified by a search through a DNA profile database, or the sample found at the crime scene may be a mixture of body fluids from more than one person. More advanced statistical methods are required in such situations.
Another role of a forensic statistician relates to sampling problems and determination of sample size. In some cases, it is necessary to examine a consignment of similar-looking items, and it is often not practical to examine every item. This may be purely on financial grounds but may be on health grounds also. The question then arises as to how many items should be examined on a sampling basis.
Finally, an important part of being a forensic statistician, as indeed it is for any statistician, is the ability to communicate results effectively to non-statisticians. Forensic statisticians may be required to attend court cases as “expert witnesses”. This involves reporting calculated probabilities, or other statistical measures, to the jury, and explaining to them how the calculations were performed. This is a challenge in itself, as the jury will typically consist of people who have little knowledge of statistical methods, and is further complicated by the need to choose careful wording (so as not to “lead” the jury into a decision on guilt or innocence of a defendant).
Our team has experience in the following:
1. Y-STR
Y-STR is a short tandem repeat (STR) on the Y-chromosome. Y-STRs are often used in forensics, paternity, and genealogical DNA testin.Y-STRs are taken specifically from the male Y chromosome. These Y-STRs provide a weaker analysis than autosomal STRs because the Y chromosome is only found in males, which are only passed down by the father, making the Y chromosome in any paternal line practically identical. This causes a significantly smaller amount of distinction between Y-STR samples. Autosomal STRs provide a much stronger analytical power because of the random matching that occurs between pairs of chromosomes during the zygote making process.
2. MITOCHANDRIAL
In multi-cellular organisms,mtDNA is inherited from the mother (maternally inherited). Mechanisms for this include simple dilution (an egg contains on average 200,000 mtDNA molecules, whereas a healthy human sperm was reported to contain on average 5 molecules, degradation of sperm mtDNA in the male genital tract, in the fertilized egg, and, at least in a few organisms, failure of sperm mtDNA to enter the egg. Whatever the mechanism, this single parent ( uni-parental inheritance)pattern of mtDNA inheritance is found in most animals, most plants and in fungi as well.
3. AUTOSOMAL DNA
Autosomal DNA is inherited form both parents. Autosomal DNA test may be taken buy either a male or a female. Short tandem repeat (STR) markers on the autosomal chromosomes havebeen used in academic population genetics studies and for extended forensic and sibling studies.
Pricing
We offer per-project and hourly pricing, so that you will know the precise cost for our services before we begin working. There will be no hidden fees or surprises along the way. The initial consultation is free if you are uncertain about the prospect of hiring a statistical consultant or what the cost might be. We also pride on providing fast turn-around time and outstanding statistical services.
Confidentiality
We greatly understand the importance of keeping data confidential. All communication, information, and data are dealt with as "Strictly Confidential" and no information will be released to any other person or third party. You retain all the property rights of your data and any results coming out of the statistical analysis. I will not ask or require any personal, financial or affiliation information from you.