Prosecutor says aggravating circumstances could bring death penalty for accused killer Roberto C. Martinez-Marineroa, 25
Credit: Omaha Police

A prosecutor says a Nebraska man – now facing two first-degree murder charges – threw his 5-year-old half brother from a bridge into a river and to his death “in an effort to conceal” the killing of their mother.

Due to “aggravating” circumstances that include the multiple murders and an effort to eliminate a witness, Douglas County Attorney Donald Kleine told the media at a news conference Monday that prosecutors would consider the death penalty for Roberto C. Martinez-Marinero, 25, who was arrested Thursday after implicating himself.

His mother, Jesus Ismenia Marinero, 45 and her youngest sons, 5-year-old Josue Ramirez-Marinero and 11-month-old Angel Ramirez-Marinero, disappeared last Tuesday.

Angel was recovered unharmed on Wednesday in a dumpster, the same day the mother’s body was discovered in a ditch. She had been hit in the face by a baseball bat and stabbed “multiple times,” Kleine said.

He also said that Josue was alive when Roberto threw him over a guardrail into the Elkhorn River.

Earlier Monday, authorities recovered the body of Josue. They had been searching the river since Thursday, based upon Roberto’s alleged statements after he walked into the Douglas County Department of Corrections that night and “advised staff that he was involved in the death of his mother.”

“With regard to motive, I think there is still a lot of work to be done,” the prosecutor said. “It’s hard to imagine what was going through anybody’s mind.”

After the older son’s alleged confession, the father of Josue and Angel told PEOPLE he had nothing to say to the alleged killer.

“For me, he’s dead,” says Jose Ramirez.

In addition to Roberto, Omaha police arrested Gabriela Guevara, 24, with whom Roberto has two children. She has been charged as an accessory for her role in misleading police and removing evidence, Kleine said.

The family of the victims now is focused on the surviving infant.

After Angel’s recovery on Wednesday and a brief hospitalization, “he’s doing okay,” says Marinero’s niece, Veronica Rosa, 27.

“He’s an 11-month-old baby. I know that he knows something is wrong. He can’t say anything. Of course he’s going to think something’s wrong when he doesn’t see Mama around, right?”

“But we’re here for him.”

The suspects, who have not yet entered a plea, are due in court Tuesday for formal arraignment.


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.