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Term of the Month

Defining Criminal Justice Research

Welcome to NIJ’s Term of the Month. Each month we are featuring a term from our scientific research portfolios informing significant American justice system issues and solutions. 

June 2022 - Microbial Forensics

Microbial forensics is the investigation of the cloud of biological evidence humans leave behind at crime scenes that includes bacteria, fungi, viruses, and other microbial evidence. Researchers have learned over the past 20 years that each person carries a distinct microbial signature that is shed into the environment and left on objects that are touched. The number of microbes in the biological clouds that surround each of us is enormous, but because they are invisible to the eye, we are unaware of them.   

The microbial communities living in association with the human body make up an individual’s microbiome, and the bacteria alone are typically 10 times more prevalent on a body than human cells. About 3% of a person’s body mass is made up of microbes. 

The birth of microbial forensics came with the 2001 attacks in Washington, D.C. using anthrax spores. The efforts to identify the strain of anthrax established microbial forensics as an investigative tool, and since that time it has been used to detect microbial traces on phones, doorknobs, keyboards, and other objects a suspect may have touched. In the future a microbial signature may reveal details about a person’s diet, health, and drug use. 

Select Resources:

The Search for a Microbial Death Clock (article)

The Forensic Microbiome: The Invisible Traces We Leave Behind (article)

The Evidence We Leave Behind: Part 1 (podcast)   

The Evidence We Leave Behind: Part 2 (podcast) available on June 6 from NIJ’s podcast page.

NIJ Microbiome Grants 

Date Created: January 28, 2021