The mother and stepfather of a 2-year-old boy found dead on December 27 have been charged with the child’s murder, police report.

Biloxi Police initially arrested Hailey Leann Heard, 21, and her husband, Joseph David Heard, 38, and charged the couple with felony child abuse.

The charges were upgraded Thursday after the investigation uncovered more details, police say.

The investigation began after the Hailey Leann Heard called first responders in the early morning of December 27, after she claimed to have found the boy unresponsive.

The child was transported to a local hospital where he was pronounced dead.

The couple are charged with capital murder and were being held in custody with no bond.