Gibson said Sunday afternoon that the search for Montalvo had come to an unfortunate end.
"Our investigation is now switching gears from a missing persons case to a murder investigation," Gibson said.
The Sheriff's Office also began searching a second property on Henry J Avenue, which is just a few blocks away from Hixon Avenue
It is not known what investigators believe is the connection between the two properties or what they think they may find at the property on Henry J Avenue.
"Our investigation is by no means complete. We're really just beginning to uncover a lot of different facts from the case," Gibson said.
The sheriff said to anyone who might be involved that there is no rock that they can hide under and no pond that cannot be drained to find the evidence needed to find Montalvo's murderer.
Meanwhile, Otero-Rivera went before a judge for his bail hearing. He is charged with violating a no-contact order and his probation.
According to a public defender, he sent a text or called to Montalvo. He was not allowed to contact her in any way after pleading guilty to beating her up and stealing her credit cards.
A judge decided Sunday to give Otero-Rivera bail that is 10 times higher than what his attorney asked for.
Rivera, Montalvo's father-in-law, has not appeared before a judge because he is in a hospital suffering from chest pains and shortness of breath.