Des Moines police arrested an 80/35 Music Festival volunteer for theft after she was found with thousands of dollars in cash, according to a police report.

Jessica Chi Rieper, 34, of Waukee, was arrested Saturday and charged with second-degree theft.

She was stopped by police as she exited a port-a-potty, carrying a bag that contained more than $3,000 in cash, according to a police report.

Rieper was working as a volunteer at the time she was arrested. She sold beer tickets at a tent sponsored by the Greater Des Moines Music Coalition, the nonprofit group behind 80/35, and other music festivals such as Little Big Fest and Gross Domestic Product.

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Reached by phone Monday, Rieper called her arrest a misunderstanding. She said the cash was a mixture of tips earned during her shift at the tent and money she'd received from her parents.

"This is my third year volunteering and we have always received a tip out after each shift, so this was not abnormal for me to take a tip out," Rieper said.

Des Moines police began looking into activity at the music festival Friday after a member of the Greater Des Moines Music Coalition told an officer that one of the tents was missing thousands of dollars, according to a police report.

Organizers gave police the names of two people who worked at the ticket tent on Friday night. Police asked the group to let the same two volunteers work Saturday while they kept watch over their activities.

Around 4:25 p.m. Saturday, a police officer reported seeing someone "conceal a wad of cash from the till" in a bag. Rieper then took the bag and went into a portable toilet.

A second name in the report has been redacted.

Des Moines police Sgt. Jim Butler stopped Rieper when she exited the portable toilet, saying he needed to check her bag for weapons. She agreed and he discovered the wad of cash totaling $3,136, according to the report.

Rieper was arrested and officers seized the money, cellphones and a device used to record transactions via cellphone.

Police suspect Rieper may have stolen credit card data while working at the tent, the criminal complaint states.

Butler noted in his report that she offered to use her cellphone hotspot for credit card transactions when a wireless router used to establish a secure connection stopped working.

"It is unknown if subject Rieper had utilized her own cellular phone to capture patron's data while utilizing her own cellular phone as a hot spot," he wrote.

Rieper said volunteers were given no instruction on how to handle money they received from patrons purchasing drink tickets.

"We don't know where the money is going and we were never instructed on who to give it to," Rieper said. "We were simply taking money in from customers and people buying tickets. There were hands flying and grabbing cash out of the drawers."

Amedeo Rossi, 80/35 project manager, said the music festival relies on more than 500 volunteers. Organizers do not conduct criminal background checks.

"We do believe most people are volunteering with good faith," he said.

Rossi said the festival uses Square, a popular credit card processing system. There is no indication at this point that any patron's data was compromised, he said.

Rieper said she has hired an attorney and she intends to fight the theft charge.

"To be pinned for money missing when there was no money management is disheartening," Rieper said. "When you try to give your time to an organization and have them come back and do something against you doesn't make me want to further support local venues."