A couple from Texas is facing charges following the discovery of their adult son, who had special needs, buried in a shallow grave behind their Burleson home.

December Marie Mitchell and Jonathan James Mitchell have been accused of tampering with and fabricating physical evidence related to a human corpse, according to a statement released by the Burleson Police Department on Monday.

Authorities were initially called to perform a welfare check on October 14 for 26-year-old Jonathan Kinman.

During the welfare check, police received crucial information suggesting that Kinman had died and was possibly buried in the backyard of the family residence.

Following the initial investigation, December Mitchell, Kinman’s mother, and Jonathan Mitchell, his stepfather, were detained. The next morning, officers returned to the scene, where they uncovered a shallow grave containing Kinman’s body. The remains were subsequently taken to the Tarrant County Medical Examiner’s Office for an autopsy.

The investigation is ongoing as authorities await the autopsy results to determine further details.

The Mitchells remain in the Johnson County Jail, where they are being held on $250,000 bonds each.

Police declined to provide further information about the case, saying that the city of Burleson had determined that release of any further records “would interfere with the detection, investigation, or prosecution of an open or pending criminal matter,” Law&Crime reported.