BRADENTON, Fla. — A Florida man has been arrested after authorities say he attempted to sell a stolen device containing radioactive material through Facebook Marketplace, prompting a multi-agency investigation and public safety concerns.
According to the Florida Highway Patrol (FHP), 24-year-old Marco Antonio Benitez Jr. was taken into custody following an investigation involving a stolen Moisture Density Gauge, a specialized piece of equipment used in construction and engineering projects.
Investigation Began With Online Listing
The case began on May 26 when investigators with the Florida Highway Patrol’s Bureau of Criminal Investigations and Intelligence received information about a private sale listing on Facebook Marketplace.
Authorities said the device was being advertised by Benitez in the Bradenton area.
Investigators arranged an undercover meeting to purchase the equipment. However, Benitez allegedly failed to appear at the agreed location.
Radioactive Material Detected at Residence
Following the failed meeting, state troopers conducted a radiation detection screening from outside the suspect’s residence.
According to officials, the screening produced an industrial-level alert indicating the presence of radioactive material.
Investigators subsequently located and safely recovered the Moisture Density Gauge from the property.
Authorities confirmed that the device was intact and had not been damaged.
What Is a Moisture Density Gauge?
A Moisture Density Gauge is commonly used to measure soil density, asphalt composition, and moisture content during construction projects.
The device contains Cesium-137, a radioactive isotope used to perform accurate density measurements.
Experts warn that if the equipment is damaged, tampered with, or improperly handled, individuals could be exposed to harmful radiation that may cause serious health complications.
Because of the risks involved, possession and operation of the equipment are heavily regulated, and only licensed individuals are authorized to use such devices.
The Florida Highway Patrol arrested a man after an investigation into the theft of a Moisture Density Gauge, valued between $10,000 and $20,000. https://t.co/g4p5cEbCvd
— FOX 13 Tampa Bay (@FOX13News) June 4, 2026
Authorities Emphasize Public Safety
Law enforcement officials noted that radioactive devices occasionally become targets for theft due to their value or potential misuse.
The recovered gauge was estimated to be worth between $10,000 and $20,000.
Officials said no injuries or radiation-related incidents were reported during the investigation.
Criminal Charges Filed
Benitez was arrested following the recovery of the device. Authorities have not released additional details regarding potential charges beyond those connected to the theft and unlawful possession of the equipment.
The investigation remains ongoing
