BLACKSBURG, Va. >> Less than a year ago, David Eisenhauer smiled confidently into a television news camera, discussing his athletic and academic aspirations for a weekly feature on high school athletes in the Baltimore area.

“I make my personal goals achievable or just out of reach of achievable,” Eisenhauer said. “That way I’m always constantly striving to better myself.”

Now the subject of murder charges that have shocked those who know him, his university campus and the nation, Eisenhauer — blonde-haired, square-jawed and gangly — remains an enigma, the mystery compounded by his brash statement to police after his arrest: “I believe the truth can set me free.”

According to police, Eisenhauer, an 18-year-old freshman engineering student and a distance runner on the track team at Virginia Tech, kidnapped and fatally stabbed a 13-year-old girl. Another freshman, 19-year-old Natalie Keepers, is charged with being an accessory before and after the crime, and accused of helping to hide Nicole Lovell’s body off a state highway in North Carolina, two hours south of campus.

According to neighbor Stacy Snider, Nicole showed off Kik messages from her “boyfriend” along with a photo of an 18-year-old named David, and said she would sneak out that night to meet him

If Eisenhauer or Keepers had a dark side, they kept it hidden, according to those who knew them, who reacted to the allegations with a uniform sense of shock.

“When I saw her (mug shot) photo, I didn’t know who it was. I thought that was the victim, because it didn’t look anything like I knew her,” said Stan Arnold, Keepers’ high school math teacher in Columbia, Maryland. “She always came across as being bubbly and happy and excited about her future.”

Some of the most pointed comments came from a Facebook post attributed to Gaige Kern, a friend of Eisenhauer and a fellow distance runner at Virginia Tech.

“The David I knew had his faults, but this is beyond the scope of imagination,” said the note, which was addressed to Eisenhauer. “Did something happen to you that would cause a complete change, or was this newly surfaced personality always there, lurking in the shadows, hiding amidst lies? And if it was, how did you hide it so well?”

The post also mentioned that Eisenhauer had a goal of working for the Defense Advanced Research Projects Agency, which develops technology for the military. Kern told The Associated Press he wasn’t ready to discuss the post or his friendship with Eisenhauer.

Eisenhauer and Keepers went to high schools five miles apart in Columbia, a planned community between Baltimore and Washington that’s known for highly rated public schools and competitive athletics. It’s not clear when they met.

Eisenhauer, however, spent much of his childhood in Washington state, where he attended a small Christian school. His father was transferred to Maryland after his sophomore year, and his parents bought their $620,000 home in Columbia in 2013, property records show.

He started running competitively in middle school at Riverside Christian School in Yakima, Washington, which has just 320 students in preschool through 12th grade. Excelling in the classroom and on the track, he had an apparently seamless transition to Wilde Lake High School, which has 1,200 students.

His coach at Wilde Lake, Whitty Bass, raved about him in the feature for WMAR-TV, which aired last March.

“These are the ones you take a deep breath when you realize what you’ve got and say, ‘Don’t mess this up,’” Bass said.

The coach was less effusive this week at an indoor track meet in Hyattsville, Maryland, declining to comment on Eisenhauer or the allegations.

Eisenhauer was redshirted for his freshman year in track at Virginia Tech, according to a sophomore teammate, Andrew Eason. In the WMAR feature, Eisenhauer said he hoped to redshirt so he could run in college for five years.

Keepers played junior varsity soccer at Hammond High School but wasn’t a standout athlete like Eisenhauer. Her interests seemed more diverse as she joined the math team and Model United Nations and became a member of the National Honor Society and the National Science Honor Society, according to her LinkedIn profile. She acted in plays, helped direct the musical “Seussical” and taught science at a summer Bible camp.

In 2014, she interned at a NASA facility in Maryland, and she planned to double-major in aerospace and ocean engineering and naval engineering.

“My field of study is due to my fascination in the foundations of aircrafts, boats, and submarines. After college, I plan to hopefully get a job with the government or an aerospace or ocean company,” she wrote on LinkedIn.

At Virginia Tech, she joined a program for freshmen called the Hypatia Women in Engineering Learning Community. According to the school’s website, participants live in the same dorm and are required to enroll in a semester-long seminar class where they talk about professional and personal development, academic success strategies and issues related to being women in male-dominated fields.

Those who knew her said she seemed like a normal teenager in every way.

“She was talkative, she had a lot of energy,” said Mindy Niland, a 21-year-old student at Howard Community College. She said they were close in middle school, and that Keepers had slept over at her house. “We went shopping. She was really interested in guys. I don’t remember her having any violent behavior.”

Nuckols reported from Washington. Associated Press writers Allen G. Breed in Blacksburg, Jessica Gresko in Washington and Juliet Linderman in Columbia, Maryland, contributed to this report.