A 24-year-old female intern with the Colorado Geological Survey radioed for help before she went missing and a man found camping in the area was arrested after her body was found, officials said Wednesday.

Alyssa Heberton Morimoto of Denver, was mapping geological sites Tuesday in the San Isabel National Forest in a remote part of Park County, said Vince Matthews, director of the survey.

Morimoto was working with the service's Karen Houck, who is also a professor at the University of Colorado-Denver, where Morimoto was a graduate student. Houck contacted officials after responding to the distress call and finding only an empty SUV.

Robert R. Amos, 44, of Kansas, is being held at the Park County Jail on an $800,000 bond. Charges are expected to be filed in the case Monday, according to MyFoxColorado.com.

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Morimoto's body was found southwest of Antero Reservoir about 11:40 p.m. Tuesday, nearly 10 hours after she was reported missing.

Matthews said the suspect had given Houck a ride as she tried hiking out to find cell phone reception.

"I think we're extremely fortunate this isn't a double tragedy," Matthews said. "The person who gave her the ride was later identified as the suspect in Alyssa's death."

Houck and Morimoto were separated when Houck decided to hike to a ridge for lunch instead of riding there with Morimoto. When Houck realized she would be late, she radioed Morimoto. A few minutes later, Houck received a frantic return radio signal.

"She (Morimoto) was screaming, 'help me, help me.' Then the radio went dead," Matthews said.

Houck bushwhacked through thick brush and arrived at the SUV about 20 minutes later, Matthews said.

Unable to get a cell phone signal and with the SUV keys missing, Houck headed down a road toward a campground when she was approached by a man in a vehicle who gave her a ride.

Houck and the man flagged down a forest ranger who passed them on the road and the ranger contacted the Park County sheriff.

A cause of death was not released and it was unclear how far from the SUV Morimoto's body was found.

Morimoto was a Denver native and graduate of Denver Waldorf High School. She graduated from the University of Colorado-Denver and was one year from graduating with a master's degree in environmental sciences from the school. She lived in Denver with her husband and parents, Matthews said.

“It’s just a senseless waste of talent, of a great mind,” said UC-D professor Fred Chambers, who was advising her in her master’s program. “And to try to make sense of this is crazy-making.”

Houck was Morimoto's first geology professor at UCD and Houck recommended Morimoto to be her field assistant during the internship, Matthews said.

"I don't know how you can prevent something like this," Matthews said, later adding: "I worry about lions and bears all the time with our mappers, but you just don't think about this kind of evil."

Court records show Amos was convicted in 1981 of second degree murder in Kansas and under the interstate compact, came to serve his sentence in Colorado in August of 1982, said a report pn MyFoxColorado.com.

In 1992, the Department of Corrections accused Amos of attempted murder, but prosecutors declined to file charges. Amos was accused of attempted murder a second time in 1994 and pleaded down to an assault charge.

He was released from the San Carlos Correctional facility in Pueblo and paroled to Kansas in November of 2001.

The Associated Press contributed to this report.