LAS VEGAS (KLAS) — An off-duty Metro detective who noticed a truck parked at a gas pump for an extended period of time helped stop diesel fuel thieves who are accused of stealing thousands of gallons at separate gas stations on April 7, according to an arrest report.

Nearly $10,000 worth of diesel fuel was stolen from a Terrible’s Chevron station at 1785 E. Sunset Road. The off-duty officer spotted one of two trucks used by the men at another station at 8132 S. Las Vegas Boulevard, about five miles away. The amount of fuel stolen from that station was not disclosed in the arrest report.

When the officer called it in, police checked it against the description of a truck involved in the other theft and sprang into action.

Luis Gomez Medero, 41, Raidel Amador Blanco, 27, and Javier Gomez, 35, face charges of felony theft, conspiracy to commit a felony theft and disregard for the safety of persons/property.

Police described how the men disabled sensors at gas pumps, allowing them to pump as much as they wanted without the pump registering the correct amount of fuel. It appears the men put the sensors back into operation after they stopped fueling, and made numerous trips to the same pumps. They paid with prepaid gift cards rather than credit cards.

“On most cases the victim business does not realize the theft of the large amount of fuel until hours/days later,” according to an arrest report. “An audit of fuel purchased is compared to what was registered as dispensed fuel and to the remaining amount of fuel in the ground tanks to determine the amount of fuel losses.”

But when the off-duty officer called in, one suspect was arrested soon after leaving the gas station. Metro police pulled over the truck on Interstate 15 south of Russell Road and took Luis Gomez into custody. Gomez had been previously arrested in an investigation of fraudulent use of payment cards to purchase diesel fuel. He was on probation in that case.

The other truck involved in the scheme showed up at the station on S. Las Vegas Boulevard about 15 minutes after Gomez left, and officers watched it at the pump for 13 minutes before he left the station. The driver wore blue latex gloves. Torn pieces of blue latex and spilled fuel were found at the pump when officers examined the area. Officers also found the lock latch to an access door to the pump had been removed, and three security screws were removed.

Gomez Medero and Amador Blanco were arrested when their truck was stopped in a residential area. Both ran from the truck, and officers quickly apprehended Gomez Medero. A Metro air unit helped officers find Amador Blanco about 30 minutes later.

Both trucks — a white Dodge Ram and a white Chevrolet 2500 — were impounded as the investigation continues. The trucks appeared to be “heavy,” and had been modified with custom bladders to hold more fuel, according to the arrest report. The trucks were registered to other owners.

Additional charges may be filed related to the cards used in the thefts, police said.