Word of the stepmother's claim follows Onslow County Sheriff Ed Brown's statement that Lance Cpl. Maria Lauterbach, who has been missing since Dec. 14, was the victim of a crime and was set to testify at the time of her disappearance, CNN reported Thursday.
The assault claim made by Lauterbach's stepmother was mentioned in documents attached to a search warrant filed in the case. Brown said other Marines may be involved in the case and may have tampered with Lauterbach's cell phone and car.
Lauterbach, 20, was eight months pregnant when she vanished.
Brown's office said Thursday that progress has been made in the case.
"I do believe the answer is near," Brown said in a statement released by his office. "Open leads are still being investigated and more witnesses developed and interviewed. All these are bringing us closer to solving the mystery surrounding the disappearance of pregnant Marine, Maria Frances Lauterbach."