A couple in Mississippi are behind bars after authorities investigating the disappearance of an 81-year-old woman found a body buried in the backyard of their home.

The investigation began Saturday when a A family member called the Jackson Police Department to report Carol Ryan missing. The relative said Ryan was in a nursing home in Brandon, located outside of Jackson, but that nothing had been heard from her in several months. Jackson Police Chief Tyree Jones told reporters Tuesday night that the investigation led them to Ryan's former home, which was now occupied by her son, John Ryan, 50, and his wife, Samantha Ryan, 48. All three lived in the house at the same time, according to police. After obtaining a warrant, investigators searched the backyard, where cadaver dogs indicated the presence of human remains. Police brought in excavators and discovered a body wrapped in a tarp covered with concrete in a pit between six and eight feet deep, Jones said. A medical examiner will next identify the remains and determine the cause and manner of death, according to authorities. The discovered human remains had been buried. “Long before” Carol Ryan was reported missing, Jones added. The police chief indicated he did not have an estimate of how long the body remained in the defendants' backyard. The investigation into the disappearance will continue until the remains are identified as those of Carol Ryan, authorities said. Police arrested John Ryan and Samantha Ryan on one count each of desecration of a human corpse. The husband is being held in the Hinds County Jail on $100,000 bail, while his wife is being held on $75,000 bail.The investigation is ongoing and more charges may be filed as investigators uncover more evidence.