MORGANTON, N.C. (AP) — A convenience store clerk in North Carolina staged a robbery with her boyfriend at the business, used the money to buy rings hours later and made a video of their engagement at a Walmart, police said.

The case began late Monday night when convenience store clerk Callie Elizabeth Carswell told police a man entered the Big Daddy’s store carrying a long, curved knife and demanded money from her, according to a Morganton Department of Public Safety news release.

But investigators say they noticed discrepancies between her story and surveillance video from the store and they discovered it was her boyfriend, Clarence William Moore III, who entered the store demanding money.

“Carswell and Moore planned the armed robbery and stole a total of $2,960 in cash,” the news release said.

The news release said authorities searched Moore’s vehicle and found money form the store and a hand-written list of items needed to conduct the robbery. Investigators say they found the weapon and clothing Moore used during the robbery.

Authorities searched Carswell’s phone and found video of them getting engaged at Walmart early the next morning, according to the news release. Receipts showed engagement rings were purchased at the Walmart. Police Lt. Josiah Brown confirmed in an email that the stolen cash was used to buy the rings.

According to The News Herald, Carswell said outside of court Tuesday that she wasn’t involved in the robbery plan.

“I didn’t do it. ... I wasn’t involved,” she told reporters.

Police said Carswell was charged with armed robbery, misuse of 911, and filing a false police report. Moore was charged with armed robbery.