After weeks of unsuccessful searches for missing Indiana University student Lauren Spierer, the Bloomington Police Department announced Tuesday that it will no longer conduct general searches of large areas, instead limiting future searches to those based on new leads.

The shift will allow police to spend more time on investigative work in the case, Police Chief Michael Diekhoff said.

The frequency of searches for Spierer, 20, already appears to have decreased since she first disappeared June 3. At first, police and thousands of volunteers searched a five-mile radius from her last known location. Last Saturday, 615 searchers completed 99 missions to find the girl.

It is anticipated that the search headquarters at the university's McNutt Quad will be closed down by Wednesday evening, however, police told FoxNews.com that tips about Spierer continue to come in to the department.

Jason "Jay" Rosenbaum, the last person to say he saw the missing student alive, passed a polygraph test when questioned about his version of events, his attorney, James Voyles, said. Voyles said Rosenbaum has been cooperative in providing statements to police regarding Spierer's disappearance, Fox 59 reports. 

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Voyles' comments followed a New York Post report Monday that Rosenbaum hadn't been forthcoming in providing information to police and to the young woman's parents.

Spierer had been spending the night partying with friends when she disappeared.