An Alabama couple has been charged with sexually assaulting a 17-year-old female relative in order to purposefully impregnate her and then keep her baby for themselves.

Jeremy and Amanda Swann, both 29, were arrested Thursday and charged with first-degree rape, according to court records, reports CBS News.

Court records show that Amanda Swann tried to coax the mentally disabled teen into having sex with her husband so she could get pregnant and have a child for them. She also watched as the man repeatedly assault the girl.

Dallas County Investigator Janet Cole told the Selma Times-Journal that the girl was assaulted at least six times over the past month, but, apparently she never got pregnant. She screamed during each assault, but the man gagged her with a ball to keep her quiet in at least one attack, the statement reads.

Amanda Swann did nothing "because she wanted (the victim) to have a baby for her," the document states.

Jeremy Swann's mother was also arrested for allegedly knowing what was going on and failing to intervene. She was charged with contributing to the delinquency of a minor, said District Attorney Michael Jackson.

"She was present when all the sexual acts were going on," Cole said, according to the Times-Journal. "She was there. She heard the girl screaming, and she did nothing."

On Monday, the couple, who is from the Jones community in Dallas County, was arraigned and ordered held on $500,000 bond each, said Selma-based Assistant District Attorney and prosecutor Elliott Lipinsky, reports Reuters.

"It's extremely disturbing," said Lipinsky. "We're not going to stop until we can ensure that the victim gets some sort of justice."

Initially, an investigation was launched after the Swanns told the Alabama Department of Human Resources that they wanted custody of the teen because Amanda Swann's mother was sexually assaulting her. However, during a subsequent investigation, the girl told investigators that Jeremy Swann had raped her several times, Lipinsky said.