VIDEO: Lois Riess stopped at Iowa gas station the day husband's body was found

A new surveillance video of suspected murderer Lois Riess shows her stopping at a northern Iowa gas station the day her husband's body was found. 

Dodge County Sheriff's Office released surveillance video of Riess buying a sandwich at a Kum and Go gas station next to Diamond Jo Casino in Northwood, Iowa on March 23 around 6:30 p.m. In the video, Riess asks the cashier for directions heading southward. Authorities say this video is key as it is the first video that captured Riess' voice. Officials hope sharing the video will help with the nationwide search.

TIMELINE: Nationwide manhunt for Lois Riess

Investigators believe that day Riess cashed more than $10,000 in stolen and forged checks from her husband's personal and business accounts at a bank in Glenville, Minnesota. She then spent most of the day gambling at Diamond Jo Casino before stopping at the gas station. Authorities have nicknamed her "Losing Streak Lois" due to her affinity with gambling.

After leaving the gas station, her next known stop was in Fort Myers Beach, Florida where authorities believe she killed a woman named Pamela Hutchinson, assumed her identity and stole her vehicle. Riess was last seen driving a white Acura TL with the Flordia license plate Y37TAA.

Billboards have gone up in multiple states and the U.S. Marshals are now offering a $6,000 reward for information leading to Riess’ arrest.

Riess is considered to be armed and dangerous. Anyone with information on her whereabouts is urged to call 911.