Another arrest has been made in the brutal beating and sexual assault of an elderly central Iowa woman.

Manuel Eduardo Balderas, 20, was booked in the Story County Jail on Thursday, according to a listing of inmates there, for charges including sexual abuse, robbery, theft and willful injury, all felonies.

Lt. Nick Lennie, chief deputy with the Story County Sheriff's Department, said Balderas was taken into custody by Des Moines police Thursday and has been transferred to Story County.

Story County officials had previously said they were looking for Balderas and Jacob Jimenez in relation to the violent robbery of an 82-year-old Kelley woman. Luis Cruz, a 17-year-old suspect in the case who authorities believe is a younger cousin of Balderas', was taken into custody last month in Texas.

"We still believe (Jimenez) to be in the area," Lennie said Friday. "Anybody that has information on his whereabouts, we encourage them to call us and not to approach him. We consider him dangerous."

Jimenez, who officials last said was in central Iowa, is said to have been the victim's great-grandson, according to court documents.

The 18-year-old led Cruz and Balderas to his great-grandmother's home Aug. 23, 2018, and the trio tied the woman up, sexually assaulted her and beat her before going to burglarize another one of Jimenez's relatives, prosecutors believe.

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The assault victim, bloodied with a swollen and bruised face and brain bleeding, eventually freed herself from a chair she was tied to and called police. The city where the assault occurred, Kelley, is a town of about 300 people nearly 10 miles south of Ames.

Each man has been charged with first-degree sexual abuse, first-degree burglary, first-degree robbery, willful injury, two counts of theft, and operating a motor vehicle without consent. Any conviction for that sexual abuse charge means a mandatory sentence of life in prison without the possibility of parole.

Several of the electronics and jewelry taken from the two homes were found about a week later in a house that Jimenez and Balderas were hiding at during the execution of a search warrant, court records show.

Family members told authorities that Jimenez has previously burglarized his great-grandmother's home.

What happened on Aug. 23

Story County sheriff's deputies were called about midnight Aug. 23, 2018, to the 1100 block of Ford Street in Kelley for a report of an assault. The victim, an 82-year-old woman, told police she was beaten and sexually assaulted by three masked assailants who climbed through a window.

“When she confronted them, she was sprayed in the face with an unknown chemical and was unable to open her eyes," the warrant reads. "(The victim) said the men asked for money and she told them she did not have any. The men went through some other belongings, then began to punch her multiple times in her face."

The great-grandmother was eventually knocked to the ground, where she was pinned down and assaulted by each man, police say.

She was eventually "transported to the hospital where it was determined she had a brain bleed; she was hospitalized five days," court records show. A rape kit was also administered the night of the assault.

Nearly three hours later, Story County deputies were called to the 900 block of Hubbel Street, where the 82-year-old victim's daughter lives, on the report of a burglary.

Authorities believe Balderas, Cruz and Jimenez stole from the latter's grandparents as well.

"It’s likely a family member was involved in the assault since both crimes involved the same family and Jacob would have known where (his grandfather's) car was located," the document states.

The couple's car was stolen and electronics, jewelry and some cash were taken from the home. The 1998 Cadillac was eventually found abandoned in Ames near residences on Iowa State University's campus.

An informant invigorates the investigation

Authorities were told by the victims that Jimenez had stolen from his family before, but a confidential informant helped investigators build the case that led to search warrants being granted and some items being recovered.

Less than a week after the attack, one of the suspects' mothers told friends that her son was involved in a robbery and called her to talk about it. The informant told police that the mother, who has a slew of theft charges in Story County herself, reported that her son said he had blood on his pants from the incident, but he waited outside while the two others beat the woman unconscious and ransacked her home.

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The informant was able to tell investigators details about the crime confirmed by the victim.

Jimenez and Balderas both spent time hiding at an Ames home in the 100 block of Hickory Drive, the informant told police. Police went to that home more than once, records show, and on Aug. 31, Jimenez was at the house with some of the stolen items when law enforcement executed a search warrant.

Jimenez is said to have been living with his adopted mother, who also lives in Ames, and that house was searched as well. Lennie could not say what was found there, or in a Facebook search of accounts tied to Jimenez. Balderas' Facebook accounts have also been looked through.

Those looking to help with the investigation should call Sgt. Anthony Rhoad at 515-382-7529 or Central Iowa Crime Stoppers at 515-223-1400.

Follow the Register on Facebook and Twitter for more news. Tyler Davis can be contacted at 515-284-8378, tjdavis@dmreg.com or on Twitter @TDavisDMR.