Nicole Montalvo, 33, was estranged from her husband, who had a history of domestic violence charges

Nicole Montalvo
Credit: Facebook

The mother-in-law of a murdered woman, whose dismembered body was found on two properties owned by her estranged husband, has been arrested.

Osceola County Sheriff Russ Gibson held a press conference Friday, confirming to reporters that Wanda Nereida Rivera, 59, faces charges of tampering with evidence and providing false statements during the commission of a felony crime in connection with the death of 33-year-old Nicole Montalvo.

Gibson said Rivera was “emotional” after her arrest and was not cooperating with authorities, according to Fox News.

Rivera’s arrest comes less than a week after her son, Montalvo’s estranged husband Christopher Otero-Rivera, 31, and 61-year-old Angel Luis Rivera, the estranged husband’s father, were charged with premeditated murder.

Another of Rivera’s sons, Nicholas Rivera, 28, was arrested on Friday on 8 counts of child pornography and is now considered an additional “person of interest” in Montalvo’s murder, Osceola County Sheriff Russ Gibson said at a press conference Monday.

“We once spoke with him, and we were able to obtain his cellphone, and that’s how we got the information for the current charges of the child pornography,” Gibson said.

Wanda Nereida Rivera
Wanda Nereida Rivera
| Credit: Osceola County Police Department

Montalvo’s body was recovered on October 25 from a St. Cloud property where Rivera and the two men were living.

That land had been searched two days earlier, with police finding no sign of Montalvo.

The victim’s family reported her missing after she failed to pick up her son from school. They told police she was last seen heading out the door the evening of Oct. 21, on her way to drop her son off at Otero-Rivera’s residence.

During Friday’s press conference, Gibson said that more arrests were pending. “We do know other people involved in this,” he said. “It’s going to lead to more arrests. This [murder] was definitely planned, and when it took effect, people were contacted or involved in whatever role [with regard to] the remains.”

Angel Luis Rivera
Angel Luis Rivera

Gibson said that Montalvo’s body was dismembered.

“I’m so angry what these people have done to this sweet woman, at a time in her life when she felt as though she had finally broken free and was so happy to have made her first month’s rent,” Gibson said, according to FOX. “Many times, victims of domestic violence don’t know how to break free, but she was out there on her own getting it done. Now she is dead.”

“Probably the most gruesome murder scene that I have seen in my 32 years,” he said.

A motive for the alleged murder has not been disclosed, and neither has the cause of death. “It could be days or weeks to get results,” Major Jacob Ruiz of the Osceola County Sheriff’s Office tells PEOPLE. “Because it wasn’t one body found intact, it takes more time for it to be determined.”

WKMG-TV, citing court records, reports that Otero-Rivera has a history of domestic violence-related charges involving his estranged wife dating back to 2016. Those records include a 2018 charge of kidnapping, battery and aggravated assault.

Ruiz says Montalvo had split from her ex-husband last October after the domestic violence incident and was starting a new life.

“She was working two jobs and was happy to move forward with life, and this guy wasn’t letting her go. He couldn’t let her move on with life. That weekend before she disappeared, she had just paid her rent had got a new apartment with her son.”

Ruiz says Montalvo’s death has impacted her family as well as the community. “It has opened their eyes about … how dangerous domestic violence is. He was on house arrest and probation for a domestic violence incident that occurred last year. It is sad.”

WFTV spoke to his public defender, who said his client had pleaded guilty to the aggravated assault charge. He also acknowledged his client has stolen Montalvo’s credit cards.

Angel Luis Rivera
Christopher Otero Rivera
  • Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Otero-Rivera has yet to enter a plea to premeditated murder.

Local reports indicate his father is under police watch at a nearby hospital, where he was taken after complaining of chest pains and shortness of breath. The father has not entered a plea either.

PEOPLE was not immediately able to reach attorneys for the suspects.