Little is known about Sergio Martinez-Perez, who is accused of killing a 93-year-old Omaha woman and is in the United States illegally.
Martinez-Perez, 19, was formally charged Friday with first-degree murder in the rape and slaying of Louise Sollowin.
He is a native of Sonora, Mexico.
Shawn Neudauer, a spokesman for U.S. Immigration and Customs Enforcement, said Friday that federal authorities have placed a detainer on Martinez-Perez. That means that if Douglas County authorities were to release him, he would be placed in ICE custody.
Neudauer said he couldn't comment on the specifics of Martinez-Perez's immigration status, citing agency policy.
However, ICE does not place such holds on people who are legal residents.
Martinez-Perez apparently tried to enter the country in 2008, but he was caught by immigration officials and given the chance to return to Mexico on his own. He did, but he entered the United States again at some point.
Douglas County prosecutor Julie Medina on Friday said Martinez-Perez had been living in Omaha for about two months, not four months as initially reported by authorities. He told a judge earlier this week that he had been working in the area as a roofer. A current address for Martinez-Perez has not been released.
Omaha police on Friday declined to release more information, citing the ongoing investigation.
Prosecutors say Martinez-Perez entered Sollowin's home at 1921 S. 10th St. through an unlocked door early Sunday, then brutally raped and beat the woman in her bed.
Sollowin died Wednesday. According to an autopsy report, blunt force trauma — including head injuries and broken cheekbones, teeth, ribs and nose — killed her.
A Douglas County judge denied bail for Martinez-Perez.
Anything other than denying bail, Medina said, “would seriously undermine the heinous nature of the crime.”
Dressed in a bright yellow jumpsuit, Martinez-Perez showed little reaction in court.
Medina told the court Friday that Martinez-Perez went out last weekend looking for a woman to have sex with. He drank all night Saturday and his advances were rejected by a woman, leaving him “angry at women,” authorities said.
Because of that, he went prowling for a victim.
Earlier this week, Martinez-Perez was charged with first-degree sexual assault and first-degree assault and burglary.
He was charged with murder under Nebraska's felony murder rule, which applies to deaths that occur during the commission of another crime, such as sexual assault or burglary. Under that rule, he will not face a separate first-degree sexual assault or burglary charge.