GARDEN GROVE, Calif. (KABC) -- Authorities in Tijuana said two bodies have been found at the property owned by Maria Lopez and Jesus Guillen , the Garden Grove couple missing in Mexico.The couple crossed the border Jan. 10. to check on the property and had not been seen since.The attorney general's office for the state of Baja California said they are 90% sure the bodies are those of Lopez and Guillen, but they are waiting for family members to identify them. Cadaver dogs made the disturbing discovery.The couple's son in law, identified as Santiago, has been detained in connection with the crime. Authorities said he was involved in a kidnapping scheme with the couple.Authorities believe the motive was rent money the couple was collecting.Officials said Santiago was going to demand a ransom for the couple. They said the son-in-law had a criminal record in the United States and had been deported in 2012.Santiago had been charged with the disappearance of the couple and Mexican officials said he will be charged with murder as well.Garden Grove police are still working to confirm details.