"We found that there were some processes that were broken and so we reacted immediately and that led to an investigation," said Amy Wiedmaier, team leader with Heartland.
Police say surveillance video caught 20-year-old Avery Cary-Wilmes and her 26-year-old sister Anyssa Beavers stealing the gift cards in late February.
Beavers is accused of stealing 23 gift cards worth $470 between February 20th and 27th.
Cary-Wilmes is accused of stealing 55 gift cards worth $1,375 between the 18th and 25th.
Amy Weidmeyer supervises the volunteers at heartland.
"The gift shop is a volunteer based business," she said. "We do inventory, we do book keeping, all the necessary things that a business would do."
Weidmeyer says she could not comment on this investigation, but says they follow guidelines when hiring volunteers.
"We do criminal background checks on all of our adult volunteers and we also have references that are used as well," she said.
Court records claim the hospital has lost about $50,000 dollars worth of gift cards in the past three years. A spread sheet provided by the hospital shows more gift cards went missing on days the girls volunteered.
Buchanan County Prosecuting Attorney Dwight Scroggins says he cannot comment on this particular case, but says a maximum penalty for felony theft can be up to 7 years in prison.
"Above five-hundred dollars can be charged as a felony," he said.