"She wanted to help people, plain and simple," her stepfather, James Jackson, told WSB-TV. "That was her goal in life. That's all she talked about since she was young - 'I want to be able to help people.'"

Valdosta State campus police, city police and the GBI were working together to conduct interviews and collect evidence, the university said in a statement Tuesday. University officials said they couldn't release any further information.

Martinelli hopes students away at college keep in touch with their parents - and give them the passwords to social networking sites and their cell phones in case anything happens.

"If you have passcodes to your computer, your phone, please tell your parents," she said. "Don't tell everybody in the world, but tell your parents your passcodes."

She said some of the best advice parents can give students is this: "They should listen to their gut," she said. "If they walk into a situation and it's not feeling right, leave."