Police increased patrols in the area where five students were slain after crime laboratory results failed to link any suspects to the killings, a newspaper reported Wednesday.

It wasn't certain, however, whether the test results last week cleared Edward Lewis Humphrey or any other suspects in the stabbing deaths or if they just failed to support existing suspicions, The Gainesville Sun reported.Nor was it clear whether all tests had been completed, the newspaper said.

Police last week announced stepped-up night patrols where the bodies of the five students were found last month. Four victims attended the University of Florida; the fifth was a student at the city's Santa Fe Community College.

The beefed-up patrols were ordered after the task force received the results of tests and after the apparent failure of intense searches of woods frequented by Humphrey, an 18-year-old freshman at the university, the newspaper said, citing law enforcement sources it did not identify.

Among the items that had been taken by investigators for testing were pubic hair and blood samples from Humphrey and another suspect, Stephen Michael Bates, 30. They are jailed on unrelated charges; neither has been charged in the slayings.

Other items collected for testing included semen, blood and a single pubic hair found at one or more of the murder scenes and on a knife found in a milk jug at Humphrey's home in Indialantic, authorities said.

Humphrey's lawyer, J.R. Russo, told the Sun he had no knowledge of any test results.