Linking a bloodstain to a missing person by genetic inheritance

Area of Science:

• Forensic Genetics
• Population Genetics
• Molecular Biology

Background:

• Establishing familial relationships is critical in missing person cases and criminal investigations.
• Genetic marker typing offers a powerful tool for linking biological evidence to individuals.

Observation:

• Genetic marker analysis can determine if parents of a missing person are also parents of the source of a bloodstain.
• Probability calculations can be performed to assess the likelihood of a random couple matching the required genetic profile.

Findings:

• General formulas were developed for calculating probabilities using phenotype and gene frequencies.
• In a homicide case, the victim's parents were found to be among only 0.8% of couples with the bloodstain's genetic markers.

Implications:

• This genetic evidence significantly aids in criminal investigations, contributing to convictions.
• The methodology provides a robust statistical framework for forensic familial identification.