John Allen Rubio, the Brownsville father convicted of murdering his three children nearly 23 years ago, is speaking on camera for the first time in an exclusive interview with Channel 5 News.

Rubio is currently scheduled for execution in November. He is a death row inmate convicted in the beheading deaths of his three children.

In the interview, Rubio says he feels remorse for what he did.

"I miss them so much. Every day I miss them," Rubio said.

Rubio says he still remembers what happened in the hours leading up to the deaths. He says it began when his 3-year-old daughter, Julissa, was acting strangely.

"She was telling me that she was my grandmother, so she was acting weird," Rubio said. "She was screaming in a weird voice, and she was not herself. And that's when I called Angela."

Rubio believes his daughter was possessed.

In recorded video testimony, Rubio admits he killed their pet hamsters first. He then told his common-law wife at the time, Angela Camacho, that Julissa was possessed.

According to court records, Rubio ordered Camacho to go to the bathroom, where their 2-month-old daughter, Mary Jane, was decapitated. Rubio then stabbed 3-year-old Julissa to death while Camacho held her down. After having sexual intercourse, the couple killed their 1-year-old son.

Records show the two older children were not Rubio's biological children. Rubio was convicted and sentenced to death.

Cameron County District Attorney Luis Saenz says the case is difficult to understand.

"It's just horrible, and it's just hard to imagine, hard to believe, and hard to understand," Saenz said.

Saenz was not the original DA when the case was tried, but he has since argued that Rubio's execution be upheld.

Rubio and his defense attorneys are arguing that he is not competent to be executed. Saenz says they intend to prove Rubio knew what he was doing the night of the murders.

"He was competent, he is competent, and he engaged in conduct deliberately and consciously intentionally knowingly and should be executed for what he did," Saenz said.

Rubio's defense attorney, Nat Perez Jr., told Channel 5 News that a doctor found Rubio incompetent at the time of the murders.

Perez says that ahead of the second trial, the defense team approached a local bishop to see if he would testify about demonic possession within the Catholic faith.

"To see if the bishop would be willing to testify to talk about, at least within the Catholic faith, they believe in the devil and demonic possession, but the church didn't want to help us. Imagine that," Perez said.

Perez also says he is against Rubio's upcoming execution.

"In this society, John never had a chance," Perez said. "In this region we're supposed to be like predominantly Catholic community. I mean we had a deacon, a Catholic deacon on the second trial. I think if you would have let him he would have put the needle in John's arm."

The Channel 5 News original documentary "Echoes from Brownsville: The Rubio Murders" airs this Thursday without commercials at 10:30 p.m.

WATCH THE TRAILER FOR ECHOES FROM BROWNSVILLE: THE RUBIO MURDERS HERE

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