"We put the cameras in between midnight and sixin the morning. It was a covert installation,"O'Keeffe said.

Security workers gutted three sets of books andcut a square inch hole for the lens in thebinding, Fennelly said.

"They are in Russian and Hungarian books. Threeold books that are not used," he said. "Youwouldn't find them."

The cameras, which were planted in specifictrouble spots, eventually replaced the 24-hourdetail, Dowler said.

The equipment used in the investigationconsisted of Panasonic time lapse video recordersand monitors, solid state chip cameras, and Elbexminiature dome cameras. Police officials said theywatched the videos in fast forward, looking forany sign of the suspect.

"These systems are used for banks orconvenience stores. Putting [them] into books israre," said Shawn M. Valenti, president of a Lynn,Mass. security equipment company.

Murphy said the systems were chosen because"they were an effective tool that could look forthe suspect without having the numbers [ofofficers] there."

The cameras "seemed to make sense" because"trying to have someone there at the right time ispretty iffy," said Dowler. He said he consultedwith security companies, psychologists and facultymembers about the case.

Dowler said the use of the cameras was a"second choice method" compared to the undercoverdetail.

Jerry Ellis, president of EGE SecurityConsultants in Burlington, Mass., saidclosed-circuit television cameras have severaldisadvantages.

"They don't have the flexibility of scanninglike a human being," he said. "Also, no one is onthe scene to apprehend the individual. It's a veryexpensive method that does not have a highpercentage of capturing what you're looking for."

But Dowler had another view of the cameras'limitations. "They didn't work because incidentsdidn't happen in those trouble areas," he said,adding that the individual might have seen thecameras and moved to a different spot in thelibrary.

Murphy said the cameras were somewhatsuccessful because the incidents stopped soonafter the apparatus was installed.

"The two events had to be related," he said.

But police sources said the main reason thecameras did not lead to an arrest was the factthat many people, including students, knew oftheir presence.