A Mini Narrative Review on Human DNA Transfer Involving Dogs and Cats and Their Role in Forensic Investigation

Area of Science:

• Forensic Science
• Molecular Biology
• Animal Science

Background:

• Domestic animals, particularly dogs and cats, play a significant role in the transfer, persistence, prevalence, and recovery (TPPR) of human DNA.
• Understanding this role is crucial for accurate interpretation of forensic evidence.

Purpose of the Study:

• To review the current understanding of human DNA transfer mediated by household dogs and cats.
• To clarify the forensic relevance of pets as vectors of human DNA.
• To identify research gaps and considerations for future studies on DNA TPPR involving pets.

Main Methods:

• A comprehensive narrative review of existing literature was performed.
• Multiple electronic databases were searched without time restrictions.

Main Results:

• Dogs and cats efficiently acquire human DNA through brief contact, serving as primary transfer reservoirs.
• Acquired human DNA can be secondarily transferred to various surfaces and items, including clothing and vehicle interiors.
• Complex multi-step and higher-order DNA transfer events involving pets have been documented.

Conclusions:

• Sampling pets may be valuable in specific forensic scenarios, potentially aiding Bayesian network analysis.
• Generating more experimental data on variables affecting DNA TPPR in pets is essential for reducing uncertainty in probability assignments.
• Further research is highly needed to support activity-level evaluations in forensic casework involving pets.