A crime scene investigator - who has worked on over 3,000 deaths - uses his own BLOOD on social media to teach the world how to approach the job.

Jeffrey Gentry, 40, is a certified bloodstain pattern analyst and death investigator, who spends his days inspecting blood splatter at real-life crime scenes.

In his downtime, Jeffrey utilises social media and online classes to teach others about his passion.

He is one of only 60 International Association for Identification (IAI) certified bloodstain pattern analysts in the world.

Jeffrey's professional history also includes roles as an ABMDI certified Deputy Coroner death investigator, forensic toxicology analyst and forensic autopsy technician.

He has investigated, and prepared reports for, over 3000 deaths over his career, including murders, motor vehicle accidents, overdoses and suicides.

Hailing from Fresno, California, Jeffrey began his journey in death investigation in 2005, when he began working as a mortician's assistant.

Jeffrey has a hard science background, with a Bachelor's Degree in biochemistry and molecular biology and associate degrees in life science, mathematics and liberal arts.

He believes his background in science, combined with his investigative experience, made him perfect for the notoriously-difficult career as a bloodstain pattern analyst.