According to the Platte County Sheriff's office, the man used a bandana to hide is face during the robbery at the Wood Oil Convenience Store in Beverly on 92 Highway around 5:30 a.m.
Authorities said the suspect entered the store and pointed a gun at the clerk and demanded money.
He reached into the register and got away with about $850 in cash.
The suspect is believed to be in his 30's and was wearing dark pants, a light colored long sleeve button-up shirt and a light colored ball cap possibly with the Chicago Bulls logo on the front.
Anyone with information should call the Platte County Sheriff's Department at (816) 858-3521 or the TIPS Hotline at (816) 474-TIPS.
Additional surveillance photos:
Suspect entering store.
Suspect leaving store.