CASA GRANDE, Ariz. -- Pinal County sheriff's detectives are investigating the deaths of a husband and wife as a murder-suicide.The sheriff's office received a 911 call of shots fired in the 10000 block of North Baltimore Drive in Casa Grande around 4 p.m. Sunday.Deputies located the bodies of a 46-year-old man and a 45-year-old woman in a residential yard. Sheriff's spokesman Tim Gaffney said both appeared to have died from gunshot wounds. Based on evidence at the scene, detectives have determined the man shot his wife then shot himself. At this time, the motive for the shooting is not clear. The identities have not been released.The case remains under investigation.