A Missouri woman has been charged in the antifreeze poisoning death of her husband whose body was found after an arson fire at the couple’s home.The Jefferson City News-Tribune reports that Miller County authorities announced Friday that 40-year-old Amy Murray, of Iberia, has been charged with first-degree murder and armed criminal action in the death of her husband, Joshua Murray. No attorney is listed for her in online court records. Bond is set at $750,000.His body was found after the fire on Dec. 11. The State Fire Marshal’s Office and the Miller County Sheriff’s Department determined that an accelerant was used to start the fire in the master bedroom. An autopsy determined that he died of poisoning before the blaze.Cell phone records indicate Miller was at the residence 30 minutes before the fire was reported to 911. She later told investigators she took her 11-year-old son and two dogs and drove to McDonald's. Murray had been employed as a nurse at the Jefferson City Correctional Center, where she had developed a romantic relationship with an inmate, police documents state.Investigators examined recordings of phone conversations at the prison and identified the inmate as Eugene Claypool, according to the probable cause statement. Murray initially told Claypool she didn't want to be around her husband and wanted to divorce him. She later told Claypool they could get married because her husband was dead. The two also talked about getting Claypool an attorney so he could be released from prison early.Claypool is serving a life sentence for second-degree murder.