Richmond police are investigating a violent home invasion that took place on Southern Cross Drive early Wednesday morning.

A woman says men broke into her home, threatened her and then one of them sexually assaulted her.

However, the situation is more complicated, according to police.

They responded to a robbery in progress where the woman says a man put a gun in her mouth and sexually assaulted her.

As the men fled the scene, the woman grabbed a gun and ran into the backyard-- where she fired shots at them.

"After the robbery supposedly occurred, the victim had called Mr. Duerson, her boyfriend," Richmond Police Asst. Chief Rodney Richardson said.

Once Richard Duerson arrived, police say he found his car -- which was in the garage at the woman's home -- with the trunk open. Police say Duerson had money stolen from his trunk.

According to the arrest citation, he pulled a gun on the woman and her son. He demanded the money back.

Police arrested Duerson on multiple charges including wanton endangerment, fourth-degree assault and possession of a handgun by a convicted felon.

The Richmond Police Department is still working on this investigation. Police told WKYT's Caitlin Centner that another arrest may be coming.

All police know of the men accused in the initial robbery is that they were armed, and one of them may have been wearing a ski mask.