WALKER, Minn. — A 28-year-old Duluth woman is accused of filling barrels with more than $1,000 worth of gasoline at several stations in Cass County and driving off without paying.

Sapphire Torres was arrested Monday and charged Wednesday in Cass County District Court. She faces one felony count of theft and posted $600 bail. Her next court appearance is Aug. 5.

Cass County Sherriff Bryan Welk is encouraging gas stations in northern Minnesota and northern Wisconsin to report similar incidents as he suspects Torres committed additional fuel thefts in the region — including a June 4 theft of $529 at a Remer, Minn., gas station.

"When you have a gas drive-off for $530 bucks, it kind of stands out," Welk said Thursday.

The investigation began Monday evening when Swanson's Bait & Tackle in Hackensack reported a fuel theft of $260 around 8:20 p.m. Previously that night, the corner store in Backus reported a $300 drive-off.

Managers at the gas stations didn't wish to comment when contacted Thursday morning.

Hackensack and Backus are about 8 miles apart and south of Walker. Remer is on the route from Duluth to Walker. Torres was pulled over and arrested outside of Walker on Hwy. 371 in Shingobee Township.

The drive-offs Monday matched a similar description and method: A person in a Toyota pickup truck filled barrels in the flatbed and left without paying.

Charges say that during the investigation deputies learned of the gas theft at Cenex in Remer. The vehicle in photos from that theft matched the Toyota truck, which has an unusual roof rack and spotlights.

In the Remer theft, charges say the Toyota pulled a trailer with two barrels strapped inside it. The barrels matched those in the back of the truck Monday.

Welk said he hoped the ongoing investigation would uncover what Torres was doing with the gasoline.

"That's the bizarre part, I don't know. And that's what we're looking into. ... Are you selling it to make money? Is it for personal use? We don't know," he said.

"One thing is getting the word out there ... if anybody else had a same or similar incident like this to help with an investigation, because we think it's more jurisdictions involved."

Torres' criminal record in Minnesota includes a pending felony assault case in Duluth.