NORMAN — Evidence in a murder case against a couple includes their Facebook messages about how the victim was haunting them, a police detective reported.

Octavio Juan Sanchez, 35, and his wife, Desiree Sanchez, 27, were charged Thursday with first-degree murder and unlawful removal of a dead body.

They are accused of killing Margarita Juanita "Maggie" Sandoval in 2018, hiding her body for years and spending her monthly Social Security disability payments on themselves.

Police found the decomposing body in a wrapped plastic container in the basement of a Norman residence on May 13, 2021, after getting a tip.

The homeowner, Miguel Munoz, confessed he helped the couple put the body in his basement in June 2019, the Norman police detective wrote in a court affidavit.

"Munoz informed investigators ... that Octavio stated he and his wife, Desiree, killed a child molester. Munoz quoted Octavio as saying, 'Desiree started it and I had to finish it,'" the detective wrote.

The victim was the sister of Octavio Sanchez and had the cognitive abilities of a child, the investigation found. She had lived in a group home in California and later with a sister in Oklahoma. She began living with her brother at a Norman apartment in January 2019.

Police believe she was murdered sometime between Feb. 17 and April 18, 2018. She would have been 18 or 19 at the time of her death. Police believe the couple kept the wrapped body at their apartment and then at their house in Norman before it was moved to their friend's basement.

Police reported the husband and wife gave multiple conflicting stories about what happened to Sandoval. The wife told an investigator for the Oklahoma Department of Human Services in 2018 that Sandoval had gone to take out the trash and never came back.

Investigators used a search warrant to obtain Octavio Sanchez's Facebook messages.

"They found multiple conversations between Octavio and Desiree in regards to wrapping up the body with plastic and moving the body around the house due to the smell," according to the affidavit.

"Investigators also found messages of where Octavio thought the police were at the apartment complex because of the body smelling. Octavio began messaging Desiree telling her to tell the police that he did everything."

However, in one message, the husband wrote to his wife "I will kill you too" if she tells on him, according to the affidavit.

"Also in the Facebook messages, investigators learned that Desiree and Octavio believe that Margarita is haunting them.

"In one conversation Octavio tells Desiree that Margarita was not letting him get to his phone to contact her. Desiree replied ... that Margarita is only messing with him because she was not there. Desiree confirmed with Octavio that Margarita was haunting her too. Desiree told Octavio that Margarita knows what she did and that is why she is haunting them."

Prosecutors filed the murder charges after the state pathologist completed an autopsy report this month and listed the manner of death as homicide. The medical examiner reported Sandoval "died as a result of undetermined means."

Cleveland County District Attorney Greg Mashburn on Friday praised Norman police detectives for their hard work to find enough evidence to get the charges filed.

Police arrested Desiree Sanchez Thursday evening. Octavio Sanchez already was in custody, awaiting sentencing in Oklahoma City federal court for illegally possessing a firearm. Norman police found a pistol hidden in a trash can in the garage of his home on May 14, 2021.

Police searched the home as part of the investigation into Sandoval's death. Octavio Sanchez was prohibited from possessing a firearm because of a felony conviction in Arkansas.

The couple also face a federal charge accusing them of converting Sandoval's Social Security disability payments and pandemic "stimulus checks" to their own use after they were no longer providing care for her.