It happened last Thursday at the Fast Track in the 8100 block of Mansfield Hwy in southeast Tarrant County.
The video shows the suspect waiting at a locked door for about two minutes before the manager lets him in to the business.
The video from another camera inside the business shows the man grabbing the manager and leading her to the office.
The suspect left the business with a significant amount of money from the safe before leaving.
Det. Nutt says 8-liner operations are the focus of more and more crime because operators are less likely to report the crime because the gambling operations are illegal.
A Sheriff's Department spokesman says there will be a separate investigation to see if Fast Track is in violation of the law.