(CNN) -- Tori Lynn Everhart was awakened at 2 a.m. by a knock at the door to her apartment on the second floor of 1690 Paris Street in Aurora. She opened the door to find a policeman. "He said, 'You need to change,' -- I was in my pajamas -- 'and get out. There's a situation.'
"I asked, 'Well, can I get back in sometime, because I'm supposed to be moving today.'
"He said, 'We're not sure about that. That's not important. The situation is important.'"
It was not until later that the 27-year-old pharmacist learned that the situation involved James Holmes, the suspect in Friday's shooting at an Aurora movie theater in which 12 people were killed.
Holmes told police that he had set up a booby trap inside his apartment, Aurora Police Chief Dan Oates told reporters.
That apartment, Number 10, is located on the top floor of the three-story brick building, one floor above her, said Everhart, who has lived in the 12-unit building for five years. She said she had been planning to move out Friday because she had finished her degree and was ready for a change.
"I wanted to have something that was a little bit bigger and in a little safer neighborhood," she said. "It's not like true ghetto. It's not the safest neighborhood, but it's definitely improving."
Donald Robert Davis, 52, lived in Number 10 himself for about two years before moving out about a year ago. He described it as an approximately 850-square-foot, one bedroom, one bath for which he paid $525 per month, not including utilities.
Marisa McMillen, 58, moved out of Number 12 a year ago.
McMillen, whose apartment was next door to Apartment 10, said Holley Realty did a background check on her before allowing her to move in to her $500-per-month, one-bedroom apartment. But she, too, moved out about a year ago before Holmes arrived.
When she heard that her former apartment building was an address shared by the suspect in a mass killing, she said, "My first thought was that this doesn't sound like someone who lived there. I'm really shocked."
McMillen described the other tenants as typically older than 24, Holmes' age. In addition, most of the other tenants were students, said McMillen, who was studying nursing.
But Holmes was a Ph.D. candidate in the University of Colorado's neuroscience program, said Jacque Montgomery, a spokeswoman for the school's hospital, where 22 victims were being treated.
He was admitted in June 2011 and was in the process of withdrawing, she said.
The apartment building is a short walk to the school's campus.
A man who answered the phone at Holley Realty would not talk to a reporter. "We are declining to say anything right now out of respect for the victims," he said.