What needs to be clarified
Check the markers examined and alternatives compared, assessing whether an individualizing statement is justified where an identical twin exists, using laboratory documents without conducting a new genetic examination.
Materials to prepare
- Report listing STR markers and profile comparison tables
- Electropherograms, control results and description of the system used
- Documented information about the twins and questions submitted to the laboratory
What to compare
Compare the loci examined with the claimed discrimination and establish whose reference samples were obtained. Check whether the other twin was considered in the question and statistical reasoning. Separate matching selected markers, rarity among unrelated people and the ability to distinguish these twins; none substitutes for another.
Possible outcome of the analysis
A documentary review may clarify STR comparison limits and ask the laboratory about the alternative considered, sample sufficiency and the basis for further testing if differentiation is needed.
Limits of the conclusions
The review does not identify who deposited the trace or guarantee differentiation by another method. Timing, DNA transfer mechanism and circumstances of the event require separate evidence.