A Florida couple is being accused of turning a 13-year-old girl into a sex slave, isolating her from the outside world for more than five years and beating her when she wouldn't comply. Rob Johnson, 44, and his wife, Marie Johnson, 43, were arrested Tuesday and charged with felony sexual assault charges, according to NBC Miami. The couple is from Port Lucie, on Florida's Atlantic coast, about 115 miles north of Miami.

After the death of her mother, the 13-year-old girl was sent to live with the south Florida couple, but the Johnsons told her that she could only be a part of family if she had sex with them, according to Fox News. An arrest warrant stated that the girl was told to call Rob Johnson "master" and that Marie Johnson held the girl against a wall by her throat until she agreed.

Police reports also state, according to NBC Miami, that the girl was beaten repeatedly during her five year ordeal. She was beaten when she failed to follow orders or when her chores weren't finished. She was homeschooled, not allowed to use the phone and was completely shut off from the world. Rob Johnson held family Sunday school classes, citing Bible passages to validate his deeds.

The victim, now 21, was reportedly coached by the Johnsons so she knew what to say when doctors asked her about her sexual activity. The girl was able to escape her tribulation when her grandmother bought a plane ticket and the girl left for Ohio, according to the Associated Press.

The St. Lucie County Sheriff's Office stated that the Johnsons were free on bail after they both posted $60,000 bond on Tuesday. No attorney has been listed for the couple and so far, they have not responded to requests from the media.