True said that while rewards often generate many calls to the police, in most cases few provide solid evidence.

“For most of these leads, there will turn out to be nothing to that sighting,” he said.

True said police have notified agencies “up and down the [Mississippi] River so they can notify us if the body is found.”

He added that it was unlikely Wiley unintentionally fell off the bridge.

“It’s extremely difficult to fall off accidentally,” True said. “We’ve had [kids horsing around] do that in the past, but you’d have to climb up over the railings.”

Though numerous national media outlets have reported a possible link between Wiley’s disappearance and a bio-terrorist threat, True said such a connection was unlikely, despite the professor’s work with viruses. Earlier this week, two of Wiley’s Harvard colleagues emphasized that his work is unlikely to be of interest to bioterrorists.

Final test results of all forensic evidence from Wiley’s rental car will not be available for several more weeks.

True would not comment on whether fingerprints and hairs besides Wiley’s were found in the car.

The abandoned car, True said, had yellow paint on its bumper and was missing a hubcap, which police think was not lost when Wiley rented the car.

True said squad cars, patrolling the bridge frequently since Sept. 11, did not see Wiley’s car parked at 3 a.m., so his car had been parked on the bridge for no more than an hour.

True confirmed reports that Wiley, who was last seen at the hotel around midnight, had consumed alcohol that night, but said there is no current evidence that he was inebriated prior to his disappearance.

Evans, who remained at the hotel with Wiley and about six to eight others after the banquet, had bought Wiley a glass of port wine at about 10 p.m. and said Wiley may have had another glass previously, but was not drunk.

“He certainly was in complete control,” Evans said. “He was carrying the conversation.”

Evans also said that Wiley may have been particularly cheerful on the night of his disappearance, but that such emotion was typical.

“He was definitely happy and outspoken, but I’m not sure how unusual that is,” he said.