Media attention and new campus alert systems established after the mass shootings at Virginia Tech may be responsible for a recent jump in false crime reports on college campuses nationwide.

In the past two months, at least three crimes have been falsely reported at North Carolina college campuses. About a half- dozen more have been publicized across the country within the past six months.

"For some people, it's the attention-seeking. For others, it's revenge. For still others, it's the feeling of power they get by watching a college campus react," said Daniel B. Kennedy, a professor in the Criminal Justice Department at the University of Detroit Mercy. "It's like starting a fire, then sitting back and watching the commotion."

False reports that trigger campus alert systems may not cut into the budget, but they can be costly when it comes to credibility, Capt. Jon Barnwell of the N.C. State University Police Department said.

Several conversations take place at NCSU before a message is sent out through the university's campuswide alert system, Barnwell said.

"You've got to define your parameters of when you use it," he said. "You've got the situation of the person who cries wolf ... how long can you go before it's construed as 'Oh, this is a message from the Listserv, I'm going to delete it,' as opposed to 'this is something I don't get often, so I'm going to read it.' "

On Wednesday, memorial services commemorating the nation's deadliest shooting rampage will be held at the Blacksburg, Va., campus where 32 students and teachers were killed by a student gunman who later killed himself.

But the Virginia Tech killings, and a more recent shooting spree in February at Northern Illinois University that left six people dead, including the gunman, aren't the only incidents making campus officials nervous and perhaps more susceptible to hoaxes.

Three weeks after UNC-Chapel Hill student body president Eve Carson was killed, the Tar Heel campus was again on high alert. UNC-CH senior Brian Sharpe reported that a man armed with a gun had attacked him in a robbery attempt Friday morning. Campus officials sent e-mail messages to alert the campus community of possible danger.

The crime was never substantiated. Sharpe, instead, was charged with filing a false police report. A second e-mail blast debunking Sharpe's report was sent to students and staff.

Meagan Shallcross, a freshman at UNC-CH, said it was disturbing to learn that the report was fake, especially coming just weeks after Carson's death.

"It's always going to scare people, but I think it seems so disrespectful," she said.

Testing of the new components of the UNC-CH campuswide emergency alert system had been well-publicized for several weeks, spokesman Mike McFarland said. Two days before Sharpe made his claims to campus police, the campus had undergone a drill that included sounding new emergency sirens. The sirens, as well as emergency text and e-mail messages, are part of a revamped emergency alert system that campus officials designed after Hurricane Katrina.

Those drills also could have been a catalyst for Sharpe's false report, Kennedy said.

"It's just a vicious circle. Something bad happens, [and] the general publicity generates the most false reports," he said.

Shallcross did not fault campus safety officials for disseminating the false report.

"I think that they're trying to put things out there as soon as they happen," she said. "You don't expect someone to lie about it."

Six weeks earlier, on Feb. 14, a gunman killed five people and wounded 16 others in a Northern Illinois University lecture hall before taking his own life.

Several weeks later, on March 3, Matthew Haney told authorities at Appalachian State University in Boone that he had seen a gunman near the west end of campus. Schools officials sent out a campus alert and canceled evening classes. Authorities later said he made the false accusations because he feared having to pay for damage to the front door at his campus apartment. Haney was charged with filing a false police report.

Three days later, a woman told Duke University police officials she had been sexually assaulted near Duke Hospital. She later recanted, saying she had not even been near the campus at the time. Officials decided not to file charges against the woman.

Duke officials sent an alert when the report was made, said Aaron Graves, Duke's associate vice president for safety and security. Another one went out after the woman recanted.

"We have to make an announcement when there is a significant event that is reported on campus," he said. "We sent out another one when she recanted. It takes some time to investigate and pull the facts together."

Randy Young, spokesman for the UNC-CH Police Department, said though the first alert sent out was found to be inaccurate, he was pleased that investigators were able to check Sharpe's story.

"From our point of view, valid and verified information is what we want to put out, and in the end, that is what occurred," he said. "We're glad that information is out there in the hands of the university community. That supersedes anything. It's our primary goal."

(Staff writer Jesse James DeConto and news researcher Brooke Cain contributed to this report.)