OSCEOLA COUNTY, Fla. — The estranged husband and the father-in-law of Osceola County mother, Nicole Montalvo, are now charged in her murder and faced a judge Monday.

Montalvo's estranged husband Christopher Otero-Rivera and father-in-law Angel Rivera were charged with pre-meditated murder.

The two men were arrested Friday on unrelated charges, and on Sunday night, they were charged with Montalvo's murder.

Otero-Rivera will remain in jail without bond. His father did not appear before the judge Monday because he is in the hospital, though jail officials won't say why. 

On Sunday, it was learned that the human remains found Friday in St. Cloud belong to Montalvo, who was last seen Monday night, October 21. Montalvo was dropping off her 8-year-old son at the suspects' home on Hixon Avenue.

Montalvo's parents contacted law enforcement about her disappearance Wednesday, according to authorities. The Osceola County Sheriff's Office received a warrant to search the Riveras' property Thursday morning.

On Sunday, investigators uncovered what they believe to be more human remains at the Rivera’s property on Henry J. Avenue, Gibson said. That property is a few blocks from their home on Hixon Avenue.

Investigators say the human remains they uncovered on that property Friday, belong to her. And the possible human remains investigators found on Henry J. Avenue are also on the Rivera's land.

Osceola County Sheriff Russ Gibson said late Sunday evening that the investigation is far from over, saying there is still much more ground to cover and urging anyone with information to come forward now before authorities do.

"We're going to get everyone involved in this case. Everyone. Whatever role you played, however small or insignificant you think it may be, your world is closing in on you," warned Gibson.

Court documents show the estranged husband and a woman were arrested a year ago after Montalvo told deputies the two kidnapped, attacked, and robbed her.

Vigil for Nicole Montalvo

Hundreds came out to the St. Cloud lakefront Monday night, where a candlelight vigil was held in honor of Montalvo.

The Montalvo family shared how special she was with the crowd.

"Nicole was such a good mother. She was such a beautiful person, and everyone out there is a testament to that," said her father.