Details of Disappearance
De Mattos lived in the 900 block of Koae Street in Honolulu, Hawaii in 1965. He was engaged to marry Lucy Pacheco, who lived in the 1200 block of Luawai Street. Both had previous spouses who were deceased, and they had only known each other for three weeks prior to their disappearances.
The couple visited De Mattos's son on December 9, 1965 and afterwards, between 8:00 and 9:00 a.m., they went for a drive together, saying they were going to the laundromat and would return soon. De Mattos was apparently carrying between $700 and $800 in cash when they were last seen.
Pacheco called her daughter at 2:00 p.m. and told her she and De Mattos were going for a drive and would be back soon. Neither one returned. A stew was found cooking in Pacheco's apartment after she vanished.
The police initially did not take the couple's disappearances seriously, thinking they had merely eloped without telling anyone and would return eventually. Investigators became concerned after weeks passed with no sign of either person or De Mattos's gray/blue four-door 1957 Pontiac, which has the license plate number 5A-31514 and the serial number P 857H33127.
The only possible sighting of them was in a Sears, Roebuck & Co. department store in Honolulu, where a clerk claimed to have served them a month after they vanished. This sighting has not been confirmed.
Both De Mattos and Pacheco's prescriptions have not been refilled or their bank accounts accessed since their disappearances. De Mattos had $6,000 in a joint bank account he shared with his son, and was expecting more money from an apartment building he sold shortly before his disappearance. Pacheco left behind her purse and wedding ring, and both of them left their prescription medications.
Pacheco is described as a dependable woman who always kept in close contact with her teenage daughter, but none of her family members ever heard from her again after she disappeared with De Mattos.
De Mattos left behind eight grown children, and Pacheco left four. All of their children were adults, except Pacheco's youngest daughter, who was in her teens. Pacheco had postponed her planned wedding until the summer months so she could take her daughter along on the honeymoon.
Pacheco and De Mattos's cases are no longer being investigated by law enforcement due to the passage of time since they vanished, but their families have never forgotten them. It isn't clear whether they left voluntarily together, or if other factors caused their disappearances. Their cases continue to puzzle people.