Scanning Electron Microscopy Determination of String Mozzarella Cheese in Gastric Contents

Abstract

As part of a suspected homicide investigation, a sampling of the gastric contents from the victim was forwarded to the U.S. Food and Drug Administration's Forensic Chemistry Center (FCC) for analysis of specific, selected components. The victim was known to have consumed string mozzarella cheese, as a snack, less than 24 h before his disappearance and the subsequent discovery of the body. The investigation sought to confirm or dismiss speculation the victim may have been fed a meal or eaten additional food prior to his death. Analysis of the stomach contents involved examination by stereoscopic light microscopy (SLM) and isolation, processing, and analysis of suspect materials by scanning electron microscopy (SEM). Several wax-like, off-white to cream-colored objects were noted by SLM examination and removed from the gastric contents. Through a series of fixation, sectioning, drying, and coating steps, these objects were prepared for analysis by SEM. Comparison of the suspect material with laboratory control string mozzarella cheese showed excellent correlation between the analyzed samples, confirming the suspect material from the stomach contents as string mozzarella cheese.