The school unveiled its newest security initiative yesterday: 24 cameras that can alert Hopkins officials to suspicious behavior, ranging from fights to falls. The machines were originally developed for the U.S. Department of Defense and have been installed along the university's north-south corridor from 30th Street to University Parkway.

The $500,000 network is part of a security upgrade begun by Hopkins on the Homewood campus after the deaths of two undergraduates in the past year. The school has pledged at least $2 million to hire more guards, install more emergency phones and tighten entrance checks in dorms.

The cameras are perhaps the most high-tech improvement. Each is capable of swiveling 360 degrees, and they can see in the dark with a range of several blocks, said Lawrence Consalvos, senior vice president of the iXP Corp., which installed them. The company will put in eight more cameras.

Consalvos, who has worked on security issues at schools including the University of Pennsylvania, Harvard and the Massachusetts Institute of Technology, said he believes Hopkins has the most high-tech system of any U.S. campus. "We're not aware of anything else like it," he said.

Work on the camera system had started last spring, shortly before junior Christopher Elser was fatally stabbed in an off-campus fraternity house. The company sped up the process this year when senior Linda Trinh was found dead in her off-campus apartment. Elser's death remains unsolved. Police charged a man last month in Trinh's killing.

The cameras are programmed to recognize 16 actions, including someone trying to break into a building, hiding behind a tree or even slipping and falling. "A lot of this is about safety, not just security," Consalvos said.

The system will then alert a dispatcher, who can decide whether to notify Hopkins security or the police.

The system is divided into six time periods, each of which will have a different behavior recognition program. So an action that might be flagged late at night won't necessarily be noted during the daytime.

"If someone leaves a package outside a dorm at 2 a.m. and leaves quickly, that's one thing, but at 10 a.m. that's probably the FedEx guy, and it's not a big deal," Consalvos said.

Employees of iXP are monitoring the system, which has been in place about two weeks, but Hopkins employees will take over in several months. Hopkins officials say they will share information with police if they record a crime.

The cameras are not meant to police students, officials said. A student drinking a beer while walking on the street or jaywalking will not be flagged, Consalvos said.

The cameras also will not violate students' privacy, Consalvos and Hopkins administrators said. None is inside a building, and views in dorms or classrooms will be automatically blurred, he said.

Since the Sept. 11 attacks, several municipalities, including New York City, have installed security cameras. S. Daniel Carter, senior vice president of Security on Campus Inc., a nonprofit organization in King of Prussia, Pa., that monitors campus safety issues, praised Hopkins' approach.

"I think it's important that they're doing this," he said.

Students said yesterday that they were unconcerned about privacy issues. "As long as it makes it safer, I'm OK with it. Two kids have died," said Vilomi Patel, a junior biomedical engineering student.