Investigators said they are having a hard time keeping these thieves in jail because victims do not want to help with prosecution.

KATY, Texas — Half-price fuel is driving thieves to gas stations in Katy while legitimate victims unintentionally help bad guys get away.

Theft rings sneak skimmers, some Bluetooth, inside gas pumps, clone credit cards then spend up to eight hours a day pumping diesel fuel into tanks for black market buyers.

“This is just an easy way for (thieves) to make a buck,” said an undercover officer with Katy Police Department.

Police busted a group Tuesday.

They also have several cases pending from other recent arrests for similar crimes. Thieves use trucks to pump up to 500 gallons of diesel into hidden tanks, officers said.

It is happening at gas stations in Katy and surrounding areas, according to investigators.

One pick-up truck used had a toolbox in the bed converted into a fuel tank. Meanwhile, a box truck had an oversized container under its passenger side.

In the back, investigators found two large storage tanks used to carry diesel to black market buyers. Those customers include 18-wheel truckers, landscaping companies, and convenience stores, police said.

A scam involving cloned credit cards fuels it all, according to investigators.

“We’ve seen one (suspect) had as little as five (cards), another 105,” an undercover officer said.

Thieves skim numbers, load them onto gift cards then distribute to other members of their ring to shop for diesel. Some crews work full days going from gas station to gas station, police said.

However, when officers catch some suspects, some people ripped off want no part of police.

“Number one they’re suspicious of us because they’ve already been victimized,” the undercover officer told KHOU 11 News. “A lot of times (victims are) from other states and they’re a little leery to participate in prosecution. The end result of that is then the suspect goes free and they go right back out and continue to do the same thing victimizing hundreds more people in just a matter of days.”

To keep those arrested in jail longer and get hiring bonds, Katy PD works with the Texas Comptroller who can hit thieves with second-degree felony tax evasion charges.

Still, police warn people to pay attention at the pumps and help them crackdown on scammers and thieves.