Armed robbers hit two Burger King restaurants about 3.5 hours apart in Littleton late Monday and early today.
Jesus Calverio-Luna, 35, of Denver, was arrested later in connection with the second robbery.
9News reported on its website that Calverio-Luna may have been a former employee and that Burger King workers recognized his voice.
The first robbery happened 10 p.m., at 5151 South Federal Boulevard ., and two armed robbers entered the business through a back door, police said.
Two workers were forced to lie on the floor and one was struck on the head, police said. She was taken to a local hospital and treated for the injury, then released.
The robbers fled with an undisclosed amount of cash.
The second armed robbery happened at about 1:30 a.m. at 301 E. County Line Road, police said. A man with a gun confronted employees there as they were leaving the store for the night.
The employees were forced back inside and an undisclosed amount of cash was stolen, police said.
Calverio-Luna is being held at a jail in Arapahoe county on a $50,000 bond, 9News reported, on suspicion of aggravated robbery, kidnapping and theft.
Cassandra Hewlings of The Denver Post contributed to this report.
