Towards Forensic DNA Phenotyping for Predicting Visible Traits in Dogs

Area of Science:

• Forensic Science
• Genetics
• Animal Science

Background:

• Dogs are frequently involved in forensic cases, with canine DNA (e.g., hair) potentially linking victims and suspects.
• Current canine individualization relies on short tandem repeat (STR) markers, but matching references is not always possible.
• Predicting a dog's physical appearance from DNA offers valuable intelligence when direct DNA matches are absent.

Purpose of the Study:

• To explore the feasibility and suitability of canine DNA phenotyping as a forensic tool.
• To identify and evaluate genetic markers for predicting externally visible canine traits.
• To assess the potential for creating composite sketches of unknown dogs from DNA evidence.

Main Methods:

• Selected 21 genetic markers (SNPs and INDELs) with known predictive values for six key traits: coat color, pattern, structure, body size, ear shape, and tail length.
• Tested marker performance on DNA samples from dogs with documented physical characteristics across various breeds.
• Conducted a blind test using withheld appearance data to evaluate the accuracy of DNA-based trait prediction.

Main Results:

• The selected genetic markers demonstrated effectiveness in predicting various canine physical traits.
• The study successfully generated composite sketches of dogs based on DNA analysis, providing a realistic impression.
• The majority of tested markers contributed to the development of accurate visual representations.

Conclusions:

• Canine DNA phenotyping is a feasible approach to predict a dog's appearance from forensic samples.
• This technique can supplement traditional DNA profiling and eyewitness accounts in criminal investigations.
• Further evaluation of possibilities and limitations is warranted for forensic canine DNA phenotyping.