A Southern California couple who went missing in Mexico after going to collect rent money from their tenants have been found dead and presumably murdered.
The bodies of Jesus Ruben Lopez Guillen, 70, and wife Maria Teresa Lopez, 65, were discovered buried underneath the floor of a home in Tijuana on Thursday, the San Diego Union-Tribune reports.
The couple’s son-in-law, who authorities identified as “Santiago N,” was arrested in connection with their deaths the same day, according to the Tribune. Police suspect their deaths may have been over a monetary dispute, KTLA reports.
In another twist, on Saturday, Tijuana police found two additional bodies of a man and a woman buried in the same home, according to KABC. Those victims have yet to be identified.
On Sunday, a judge ordered that Santiago remain in custody on a “forced disappearance” felony charge, the Tribune reports. He has not been charged with any crimes at this point, the Tribune reports.
The couple was reported missing on Jan. 10 by their daughter after they didn’t return to their Garden Grove home. They had gone to collect rent from tenants in properties they own in the Obrera neighborhood of Tijuana. They had only planned to be there for a few hours, but were never seen again.
“They own some properties in Tijuana and they go down to collect rent and take it to the bank and there is a place where they would exchange it,” Garden Grove Police Department Lt. Carl Whitney told PEOPLE. “They were going to have the money exchanged and do a quick turnaround trip and be right back.”
The couple’s daughter told police that she tracked her parents to one of their properties using an online service, but when a relative went to check on them, they weren’t there. The phone later died.
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Tijuana police discovered the pair’s green 2005 Toyota Tundra near the rental property, Whitney said.
According to the Tribune, Santiago told authorities that he picked up the couple at the Tijuana border crossing, took them to their rental properties and later brought them to a bank to exchange the rent money into U.S. currency. He then alleged he brought the couple back to the border.
Prosecutors said they discovered “several contradictions” in his statements, the Tribune reports.