Dec. 7--The random, sudden violence that befell Omaha, Neb., on Wednesday is almost impossible to prevent without turning shopping centers into armed camps, security consultants say.

It would require the kind of security employed at airports with metal detectors at every entrance and trained, armed personnel running them.

"It's more than cost prohibitive -- it's cost impossible," said James Dallas, a Philadelphia area security consultant.

That said, such attacks are rare, and those responsible for shopping center security say they work to be as prepared as possible.

"This was not an attack against an individual mall or an attack against an industry," said Malachy Kavanagh, spokesman for the International Council of Shopping Centers in New York. "It was obviously an emotionally disturbed individual who wanted to make a very public display."

The owners of many area malls and larger retailers do not comment on specific security measures, but they say they constantly refine and look for ways to improve.